samara state aerospace university attitude dynamics and control/stabilization of spacecraft and...
TRANSCRIPT
Samara State Aerospace University
Attitude dynamics and controlstabilization of spacecraft and gyrostat-satellites
Anton V Doroshindoraninboxru
Samara 2015
Outline
bull Part 1 - Introduction to attitude dynamics and control
bull Part 2 - Research results
- the magnetized dual-spin spacecraft attitude motion
- the regular and chaotic dynamics of dual-spin spacecraft
- the multi-rotor system and multi-spin spacecraft dynamics
bull Conclusion
1
Part 1 - Introduction to Attitude
Dynamics and Control
Most of the spacecraft have instruments or antennas that must be pointed
in specific directions
ndash The Hubble must point its main telescope
ndash Communications satellites must point their antennas
The orientation of the spacecraft in the space is called its attitude
To control the attitude the spacecraft operators must have the ability to
ndash Determine the current attitude (sensorshellip)
ndash Determine the error between the current and desired attitudes
ndash Apply torques to remove the error (with the help of actuatorshellip)
2
The Spacecraft Attitude Stabilizationbull mdash Spin Stabilization methodsbull mdash Gravity Gradient Stabilization methodsbull mdash Magnetic Stabilization methodsbull mdash Aerodynamic Stabilization methods
Actuatorsbull mdash Reaction Wheel Assemblies (RWAs)bull mdash Control Moment Gyros (CMGs)bull mdash Thrusters
3
Spin stabilization4
The TopSpin stabilized spacecraft
Spin-stabilization is a method of SC stabilizing in a fixed orientation using rotational motion around SC axis (usually symmetry axis ) ndash ldquothe gyroscopic effectrdquo
Spin StabilizationDual-Spin Spacecraft
4
TACSAT I was the largest and most powerful communications satellite at the time when it was launched into synchronous orbit by a Titan IIIC booster 9 February 1969 from Cape Canaveral Florida
TACSAT I The antenna is the platform and is intended to point continuously at the Earth spinning at one evolution per orbit The cylindrical body is the rotor providing gyroscopic stability through its 60 RPM spin
Spin StabilizationDual-Spin Spacecraft
4
The dual-spin construction-scheme is quite useful in the practice during all history of space flights realization and it is possible to present some examples of the DSSC which was used in real space-programs (most of them are communications satellites and observing geostationary satellites)
- This is long-continued and well successful project ldquoIntelsatrdquo (the Intelsat II series of satellites first launched in 1966) including 8th generation of geostationary communications satellites and Intelsat VI (1991) designed and built by Hughes Aircraft Company - The ldquoMeteosatrdquo-project by European Space Research Organization (initiated with Meteosat-1 in 1977 and operated until 2007 with
Meteosat-7) also used dual-spin configuration spacecraft - Spin-stabilized spacecraft with mechanically despun antennas was applied in the framework of GEOTAIL (a collaborative mission
of Japan JAXAISAS and NASA within the program ldquoInternational Solar-Terrestrial Physicsrdquo) launched in 1992 the GEOTAIL spacecraft and its payload continue to operate in 2013
- Analogously the construction scheme with despun antenna was selected for Chinese communications satellites DFH-2 (STW-3 1988 STW-4 1988 STW-55 1990)
- Well-known Galileo missionrsquos spacecraft (the fifth spacecraft to visit Jupiter launched on October 19 1989) was designed by dual-spin scheme
- Of course we need to indicate one of the worlds most-purchased commercial communications satellite models such as Hughes Boeing HS-376 BSS-376 (for example Satellite Business Systems with projects SBS 1 2 3 4 5 6 HGS 5 etc) they have spun section containing propulsion system solar drums and despun section containing the satellites communications payload and antennas
- Also very popular and versatile dual-spin models are Hughes HS-381 (Leasat project) HS-389 (Intelsat project) HS-393 (JCSat project)
The DSSC usually is used for the attitude stabilization by partial twist method only one of the DSSCs coaxial bodies (the laquorotorraquo-body) has rotation at the laquoquiescenceraquo of the second body (the laquoplatformraquo-body) ndash it allows to place into the laquoplatformraquo-body some exploratory equipment and to perform of space-mission tests without rotational disturbances
Spin StabilizationDual-Spin Spacecraft
4
HS 376Class Communications Nation USA
Mass 654 kg at beginning-of-life in geosynchronous orbit
Spin stabilized at 50 rpm by 4 hydrazine thrusters with 136 kg propellant Star 30 apogee kick motor Solar cells mounted on outside of cylindrical satellite body provide 990 W of power and recharge two NiCd batteries 24 + 6 backup 9 W transmission beams
HS 376 Chronology- 15 November 1980 SBS 1 Program- hellip- 22 November 1998 BONUM-1 Program
Spin StabilizationDual-Spin Spacecraft
4
Hughes HS-389
Intelsat-6 [Boeing] SDS-2 [NRO]
Ordered Date
Intelsat 601 1982 29101991
Intelsat 602 1982 27101989
Intelsat 603 1982 14031990
Intelsat 604 1982 23061990
Intelsat 605 1982 14081991
SDS-2 1 08081989
SDS-2 2 15111990
SDS-2 3 02121992
SDS-2 4 03071996
Gravity Gradient Stabilization 5
UniCubeSat-GG is the first CubeSat mission of GAUSS (Gruppo di Astrodinamica dell Universita degli Studi ldquola Sapienzardquo) at the University of Rome (Universita di Roma ldquoLa Sapienzardquo Scuola di Ingegneria Aerospaziale) Italy
The Gravity-gradient stabilization is a method of SC stabilizing in a fixed orientation using only the orbited bodys mass distribution and the Earths gravitational field
SC is placed along the radius-vector of the Earth
Tether-satellitesPhysical pendulums
Magnetic Stabilization 6
Magnetic stabilization is a method of SC stabilizing using geomagnetic field of the Earth
SC is positioned along the magnetic lines of the geomagnetic field (ldquomagnetic compassrdquo)
One of Four Alinco-5 Permanent Magnet sets on board KySat-1
KySat-1 Passive Magnetic Stabilization System is used for antenna orientation and coarse camera pointing
KySat-1 the first satellite project by Kentucky Space is a 1-U CubeSat scheduled to launch in 2010 on a NASA mission
Aerodynamic Stabilization 7
The Aerodynamic stabilization is a method of SC stabilizing using aerodynamic force in rarefied atmosphere of low earth orbit
SC is positioned along the orbital velocity vector
Aerodynamically Stable CubeSat Design Concept
ldquogo like an arrow helliprdquo
SC with tail unit
Actuators 8Reaction Wheel Assemblies (RWAs)
RWAs are particularly useful when the spacecraft must be rotated by very small amounts such as keeping a telescope pointed at a star
This is accomplished by equipping the spacecraft with an electric motor attached to a flywheel which when rotated increasingly fast causes the spacecraft to spin the other way in a proportional amount by conservation of angular momentum
Actuators 9Control Moment Gyros (CMGs)
A CMG consists of a spinning rotor and one or more motorized gimbals that tilt the rotorrsquos angular momentum As the rotor tilts the changing angular momentum causes a gyroscopic torque that rotates the spacecraft
Microsatellite with four control moment gyroscopes
Actuators 10Thrusters
A thruster is a small propulsive device used by spacecraft for attitude control in the reaction control system or long-duration low-thrust acceleration
Liquefied gases in high-pressure balloons
Main Equations of Angular Motion of Rigid Body(Attitude Motion of SC)
11
Euler dynamical equations
Euler kinematical equations
The study of the angular motion of the SC attitude dynamics is one of the main problems of rigid body systems dynamics in the classical mechanics
And vice versa
Tasks of analysis and synthesis of the rigid bodiesrsquo motion have important applications in the space-flight dynamics
Main Properties of the Free Angular Motion of Rigid Body(Attitude Motion of SC)
12
Louis Poinsot interpreacutetation
Inertia tensor with polhodes
--- notation by CDHall
Main Properties of the Free Angular Motion of Rigid Body(Attitude Motion of SC)
12
If we consider rigid body angular motion on the base of Hamilton dynamics than for rigid body motion we take pendulum phase structure
x=tetta (nutation) and
y = impulse (tetta) ~ d(tetta)dt
Pendulum phase space
Part 2 ndash Research Results
1 The magnetized dual-spin spacecraft attitude motion
2 The regular and chaotic dynamics of dual-spin spacecraft
3 The multi-rotor system and multi-spin spacecraft dynamics
13
14
Letrsquos consider an angular motion (about point O) of spider-type multiple rotor rigid bodies systems and
coaxial bodies systems
Mechanical models of multiple-rotor systems
Coaxial bodies system(dual-spin spacecraft)
Multirotor spiders(gyrostat-spacecrafts)
Number of rotors = N
Number of rotors = 6 Number of rotors = 1
1cos sin
cos
sin cos
sincos sin
cos
p q
p q
r p q
(1)
(2)
15
I1 The angular motion general equations
I The coaxial bodies system motion
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
cos sinP
P Q M Q
The coaxial top
I2 The angular motion equations of the magnetic DSSC and the coaxial Lagrange top
16
The single dipole model of the Earthrsquos magnetic field and the constant magnetic field vector corresponding to the circle equatorial orbit
The magnetic DSSC coordinate frames
17I3 The equations
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
2 2 2
2 1
0
T
x y zOx y z
T
orb orb
M M M
B m B m
oθ
θ
rbM m B
M
1 2
2 2
3 2
cos
cos
cos
OZ Ox
OZ Oy
OZ Oz
i k
j k
k k
2 2
2 1
2
0
Ap C B qr q Q
Bq A C pr p Q
C r B A pq M
orbQ B m
1
22 2 2 2 22
1 2 1 2 1 2
sin cos 1
2 2
T P
LI L l lT
A A A B C C
H H
cos sinP
P Q M Q
(6)
(5)
(4)
(3)
(2)
(1)
18I4 The integrals and solutions
2
2
2
1
2
23
x
y
z
K Ap
K KK Bq
K KK C r
K K
2
2
2
2 3
2
const
cos
z
z
L K C r
I I K
K C rL
K K K
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
2
2 2 22 2
1
2 2Ap Bq C r E C r TC
22 2 2 2 22 2A p B q C r K DT
2 1 2
22 21
2
22 2
Bq A C f q f q
C B C Ff q V E
A A B A A B
H B A B qf q V V
C A C
- AV Doroshin Exact Solutions in Attitude Dynamics of a Magnetic Dual-Spin Spacecraft and a Generalization of the Lagrange Top WSEAS Transactions on Systems Issue 10 Volume 12 (2013)
471-482
(11) (10)
(9)
(8) (7)
19I5 The analytical solution
The polhodes ellipsoid
2
2 2
22 2
2 1
1
1
q t H C A C x t SB A B
p t C B C x t FA A B
EAr t x t S t r t
A C C
2 20 0
2 20 0
sn
sn
i
i
R P c N t t I kx t e
R P c N t t I k
S E
The numerical integration (lines) and analytical (points) results
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075 q0=2 r0=583 [1s] K=50
[kgm2s] Q=100 [kgm2s2]
5
(13)
(12)
20I6 The analytical solution for Euler angles
orbB
K2K + ω timesK = mtimesK
K + ΩtimesK = 0
orbB
K 2Ω ω m
γ + Ωtimes γ = 0
1
2
3 2
t Ap t K
t Bq t K
C r t K
2cos
tg
t C r t K
Ap tt
Bq t
0
0
2 2
0 2 2 2 2
01
( ) ( )
( ) ( )
( )
t
t
t
t
Ap t Bq tt K dt
A p t B q t
t r t dtC
5
10 20 3003 052 08
The numerical integration (lines) and analytical (points) results for the directional cosines
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075
q0=2 r0=583 [1s] K=50 [km2s]
Q=100 [kgm2s2]
(19)
(20)
(18) (17)
(16)
(15)
(14)
21I7 Hamilton form of equations in the Andoyer-Deprit variables
(21)
(25)
(22)
(23)
(24)
1 C r
22
3 23
T T
T
L I Kl
I L I
K k K s K
K k
2
2
2
2 22
2 22
2
sin
cos
x
y
z
K Ap I L l
K Bq I L l
K C r L
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
22 2 2 2 22
1 2 1 2 1 2 2
sin cos 1
2 2
LI L l l LQ
A A A B C C I
H
22
(26)
Hamilton form of equations 2 2 2 1 1A B C A C
Equations (21) have heteroclinic solutions
Perturbations
0 0 L lM t f l t L t g t t dt
Melnikov function
(28)
The Melnikov function has the infinite number of simple roots This proves the fact of the motion chaotization at the presence of small harmonic perturbations
22 2 2 2
2 1
C B C EB
p t y t q t s k y t E r t y t t r tA A B B C C
0
sin cosN
n p n pn
Q t a n t b n t
22 2 2 2 2
20 0
1 2 1 2 1 2 2 20 1 0 1
sin cos 1
2 2
LI L l l L LQ Q Q t
A A A B C C I I
H H H H H
0 0 1 1
L L
L l L l
l l
L f l L gf f g g
l L l Ll f l L g
H H H H
0 0 00
cos sinN
ns n p n p
n
M t J a n t b n t
(27)
(26)
00 0 2
2
00 1 2 02
4 exp
exp 4
M aa E y t
ky t
Mt aE y a a a
k
23
2 l L I
I8 Numerical modeling Poincareacute sections mod 2 0pt
2 22 2 2 1 1 2 1 3 5
0 0 0 0
15 10 6 5 4[ ] 20 5 [ ] 075 [1 ] 1 5 20 [1]
) 5 004 ) 5 01 ) 10 01 ) 15 02
pA B C A C kg m I kg m s s a a a
a Q b Q c Q d Q
(a) (b)
(c) (d)
II The spider-type systems motion 24
m r K K K
1 2
3 4
5 6
4 2 m r
Ap p
Bq J I q I
Cr r
K K
ed
dt
Kω K M
12 56 34
34 12 56
56 34 12
ex
ey
ez
Ap I C B qr I q r M
Bq I A C pr I r p M
Cr I B A pq I p q M
4 2
4 2 4 2
iji j A A J I
B B J I C C J I
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i ex x
i e i ey y
i e i ez z
I p M M I p M M
I q M M I q M M
I r M M I r M M
(1)
(2)
(3)
(4)
II1 Angular momentum of the system in projections onto axes of the frame Oxyz
II2 The motion equations of the multirotor system
25
1 1
1 1
4 2
4 2 4 2
N Nij
il jl ll l
N N
l ll l
A A J NI
B B J NI C C J NI
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i el l lx l l lx
i e i el l ly l l ly
i e i el l lz l l lz
I p M M I p M M
I q M M I q M M
I r M M I r M M
0
1
2
3
cos 2
cos sin2
cos sin2
cos sin2
2 λ Θ λ
0
1
2
3
0
0
0
0
p q r
p r q
q r p
r q p
λ Θ
(4rsquo)
II3 The Euler parameters
(5)
26II4 The conjugate spinups and captures
Def1 Conjugate rotors are paired rotors located in the same layer on the opposite rays For example rotor 3N and rotor 4N are conjugate rotors (also rotor 12 and rotor 22 etc)
Def2 Conjugate spinup mean a process of spinning up conjugate rotors in opposite directions up to a desired value of relative angular velocity with the help of internal moments from main body Velocities of conjugate rotors will be equal in absolute value and opposite in sign
Def3 Rotor capture is an immediate deceleration of rotor relative angular velocity with the help of internal moment from the main body So rotor capture means an ldquoinstantaneous freezingrdquo of rotor with respect to the main body The capture can be performed with the help of gear meshing friction clutch or other methods
27
(6)
II6 Analytical solutions of motion equations
0e e ex y zM M M
A B C D
12 121
12 122
0
0
0
0
si
si
M if t tM
otherwise
M if t tM
otherwise
12 12 12sS M t I
1 12 2 12S S
1 1 12c c st t t
1 0
12
122
ISp
A IAS
A I
1 0 Conjugate spinup of rotors 1 2
Rotor 1 capture
Rotor 2 capture
2 2 1c c ct t t
1 2
121 2
0 0
c c
c c
t t tp IS
P t t tA I
Two serial captures of conjugate rotors bring to piecewise constant angular velocity of the main body
The main body performed the rotation about Ox axis by finite angle 12 2 1
c c
x
IS t t
A I
28
1 3 5 2 4 6
0 1 2 3
1 0
c c c c c c c cstart finish
c c c cstart start start start
t t t t t t t t
t t t t
0 1
2 3
2 2 2
cos sin2 2
sin sin2 2
c cstart start
c cstart start
c c c cstart finish finish start
t t t tPt t
t t t tQ Rt t
P Q R t t t T t t
1 2 t t t p P q Q r R
Letrsquos assume synchronically captures of coresponded conjugate rotors 1 2 3 4 5 6 and coincidence of the frame Oxyz initial position and the fixed frame OXYZ
Angular velocities between conjugate captures of rotors
Solutions of kinematic equations (5)
cos cos cosT
P Q R
T
e
The main body performed finite rotation about vector e by angle χ
(18)
(20)
(19)
(21)
29II7 Numerical simulation of reorientation process
const 0 1 135 246
i s cj jj j j
i s cj jj j j
jj
M M H t H t t H t t
M M H t H t t H t t
M j j
Two sets of results of numerical simulation
1 4 5(0) (0) (0) 0 (0) 100 1 s ω
ν = 300 Nms
H(t) is Heaviside function
FigA - zero value of angular momentum and different inertia moments of main body
Fig A Fig B
Fig4 - reorientation process at nonzero system angular momentum
30
__________________________________________________________
The main properties of the attitude stabilization and control of SC (and multirotor systems) have been examined
Research into attitude motion of the one-body-SC dual-spin SC and spider-type-SC is very complicated
Nontrivial and chaotic modes are possible in the SC attitude motion
Conclusion
- Slide 1
- Outline
- Part 1 - Introduction to Attitude Dynamics and Control
- Slide 4
- Spin stabilization
- Spin Stabilization Dual-Spin Spacecraft
- Spin Stabilization Dual-Spin Spacecraft (2)
- Spin Stabilization Dual-Spin Spacecraft (3)
- Spin Stabilization Dual-Spin Spacecraft (4)
- Gravity Gradient Stabilization
- Magnetic Stabilization
- Aerodynamic Stabilization
- Actuators
- Actuators (2)
- Actuators (3)
- Main Equations of Angular Motion of Rigid Body (Attitude Motion
- Main Properties of the Free Angular Motion of Rigid Body (Attit
- Main Properties of the Free Angular Motion of Rigid Body (Attit (2)
- Part 2 ndash Research Results
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
-
Outline
bull Part 1 - Introduction to attitude dynamics and control
bull Part 2 - Research results
- the magnetized dual-spin spacecraft attitude motion
- the regular and chaotic dynamics of dual-spin spacecraft
- the multi-rotor system and multi-spin spacecraft dynamics
bull Conclusion
1
Part 1 - Introduction to Attitude
Dynamics and Control
Most of the spacecraft have instruments or antennas that must be pointed
in specific directions
ndash The Hubble must point its main telescope
ndash Communications satellites must point their antennas
The orientation of the spacecraft in the space is called its attitude
To control the attitude the spacecraft operators must have the ability to
ndash Determine the current attitude (sensorshellip)
ndash Determine the error between the current and desired attitudes
ndash Apply torques to remove the error (with the help of actuatorshellip)
2
The Spacecraft Attitude Stabilizationbull mdash Spin Stabilization methodsbull mdash Gravity Gradient Stabilization methodsbull mdash Magnetic Stabilization methodsbull mdash Aerodynamic Stabilization methods
Actuatorsbull mdash Reaction Wheel Assemblies (RWAs)bull mdash Control Moment Gyros (CMGs)bull mdash Thrusters
3
Spin stabilization4
The TopSpin stabilized spacecraft
Spin-stabilization is a method of SC stabilizing in a fixed orientation using rotational motion around SC axis (usually symmetry axis ) ndash ldquothe gyroscopic effectrdquo
Spin StabilizationDual-Spin Spacecraft
4
TACSAT I was the largest and most powerful communications satellite at the time when it was launched into synchronous orbit by a Titan IIIC booster 9 February 1969 from Cape Canaveral Florida
TACSAT I The antenna is the platform and is intended to point continuously at the Earth spinning at one evolution per orbit The cylindrical body is the rotor providing gyroscopic stability through its 60 RPM spin
Spin StabilizationDual-Spin Spacecraft
4
The dual-spin construction-scheme is quite useful in the practice during all history of space flights realization and it is possible to present some examples of the DSSC which was used in real space-programs (most of them are communications satellites and observing geostationary satellites)
- This is long-continued and well successful project ldquoIntelsatrdquo (the Intelsat II series of satellites first launched in 1966) including 8th generation of geostationary communications satellites and Intelsat VI (1991) designed and built by Hughes Aircraft Company - The ldquoMeteosatrdquo-project by European Space Research Organization (initiated with Meteosat-1 in 1977 and operated until 2007 with
Meteosat-7) also used dual-spin configuration spacecraft - Spin-stabilized spacecraft with mechanically despun antennas was applied in the framework of GEOTAIL (a collaborative mission
of Japan JAXAISAS and NASA within the program ldquoInternational Solar-Terrestrial Physicsrdquo) launched in 1992 the GEOTAIL spacecraft and its payload continue to operate in 2013
- Analogously the construction scheme with despun antenna was selected for Chinese communications satellites DFH-2 (STW-3 1988 STW-4 1988 STW-55 1990)
- Well-known Galileo missionrsquos spacecraft (the fifth spacecraft to visit Jupiter launched on October 19 1989) was designed by dual-spin scheme
- Of course we need to indicate one of the worlds most-purchased commercial communications satellite models such as Hughes Boeing HS-376 BSS-376 (for example Satellite Business Systems with projects SBS 1 2 3 4 5 6 HGS 5 etc) they have spun section containing propulsion system solar drums and despun section containing the satellites communications payload and antennas
- Also very popular and versatile dual-spin models are Hughes HS-381 (Leasat project) HS-389 (Intelsat project) HS-393 (JCSat project)
The DSSC usually is used for the attitude stabilization by partial twist method only one of the DSSCs coaxial bodies (the laquorotorraquo-body) has rotation at the laquoquiescenceraquo of the second body (the laquoplatformraquo-body) ndash it allows to place into the laquoplatformraquo-body some exploratory equipment and to perform of space-mission tests without rotational disturbances
Spin StabilizationDual-Spin Spacecraft
4
HS 376Class Communications Nation USA
Mass 654 kg at beginning-of-life in geosynchronous orbit
Spin stabilized at 50 rpm by 4 hydrazine thrusters with 136 kg propellant Star 30 apogee kick motor Solar cells mounted on outside of cylindrical satellite body provide 990 W of power and recharge two NiCd batteries 24 + 6 backup 9 W transmission beams
HS 376 Chronology- 15 November 1980 SBS 1 Program- hellip- 22 November 1998 BONUM-1 Program
Spin StabilizationDual-Spin Spacecraft
4
Hughes HS-389
Intelsat-6 [Boeing] SDS-2 [NRO]
Ordered Date
Intelsat 601 1982 29101991
Intelsat 602 1982 27101989
Intelsat 603 1982 14031990
Intelsat 604 1982 23061990
Intelsat 605 1982 14081991
SDS-2 1 08081989
SDS-2 2 15111990
SDS-2 3 02121992
SDS-2 4 03071996
Gravity Gradient Stabilization 5
UniCubeSat-GG is the first CubeSat mission of GAUSS (Gruppo di Astrodinamica dell Universita degli Studi ldquola Sapienzardquo) at the University of Rome (Universita di Roma ldquoLa Sapienzardquo Scuola di Ingegneria Aerospaziale) Italy
The Gravity-gradient stabilization is a method of SC stabilizing in a fixed orientation using only the orbited bodys mass distribution and the Earths gravitational field
SC is placed along the radius-vector of the Earth
Tether-satellitesPhysical pendulums
Magnetic Stabilization 6
Magnetic stabilization is a method of SC stabilizing using geomagnetic field of the Earth
SC is positioned along the magnetic lines of the geomagnetic field (ldquomagnetic compassrdquo)
One of Four Alinco-5 Permanent Magnet sets on board KySat-1
KySat-1 Passive Magnetic Stabilization System is used for antenna orientation and coarse camera pointing
KySat-1 the first satellite project by Kentucky Space is a 1-U CubeSat scheduled to launch in 2010 on a NASA mission
Aerodynamic Stabilization 7
The Aerodynamic stabilization is a method of SC stabilizing using aerodynamic force in rarefied atmosphere of low earth orbit
SC is positioned along the orbital velocity vector
Aerodynamically Stable CubeSat Design Concept
ldquogo like an arrow helliprdquo
SC with tail unit
Actuators 8Reaction Wheel Assemblies (RWAs)
RWAs are particularly useful when the spacecraft must be rotated by very small amounts such as keeping a telescope pointed at a star
This is accomplished by equipping the spacecraft with an electric motor attached to a flywheel which when rotated increasingly fast causes the spacecraft to spin the other way in a proportional amount by conservation of angular momentum
Actuators 9Control Moment Gyros (CMGs)
A CMG consists of a spinning rotor and one or more motorized gimbals that tilt the rotorrsquos angular momentum As the rotor tilts the changing angular momentum causes a gyroscopic torque that rotates the spacecraft
Microsatellite with four control moment gyroscopes
Actuators 10Thrusters
A thruster is a small propulsive device used by spacecraft for attitude control in the reaction control system or long-duration low-thrust acceleration
Liquefied gases in high-pressure balloons
Main Equations of Angular Motion of Rigid Body(Attitude Motion of SC)
11
Euler dynamical equations
Euler kinematical equations
The study of the angular motion of the SC attitude dynamics is one of the main problems of rigid body systems dynamics in the classical mechanics
And vice versa
Tasks of analysis and synthesis of the rigid bodiesrsquo motion have important applications in the space-flight dynamics
Main Properties of the Free Angular Motion of Rigid Body(Attitude Motion of SC)
12
Louis Poinsot interpreacutetation
Inertia tensor with polhodes
--- notation by CDHall
Main Properties of the Free Angular Motion of Rigid Body(Attitude Motion of SC)
12
If we consider rigid body angular motion on the base of Hamilton dynamics than for rigid body motion we take pendulum phase structure
x=tetta (nutation) and
y = impulse (tetta) ~ d(tetta)dt
Pendulum phase space
Part 2 ndash Research Results
1 The magnetized dual-spin spacecraft attitude motion
2 The regular and chaotic dynamics of dual-spin spacecraft
3 The multi-rotor system and multi-spin spacecraft dynamics
13
14
Letrsquos consider an angular motion (about point O) of spider-type multiple rotor rigid bodies systems and
coaxial bodies systems
Mechanical models of multiple-rotor systems
Coaxial bodies system(dual-spin spacecraft)
Multirotor spiders(gyrostat-spacecrafts)
Number of rotors = N
Number of rotors = 6 Number of rotors = 1
1cos sin
cos
sin cos
sincos sin
cos
p q
p q
r p q
(1)
(2)
15
I1 The angular motion general equations
I The coaxial bodies system motion
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
cos sinP
P Q M Q
The coaxial top
I2 The angular motion equations of the magnetic DSSC and the coaxial Lagrange top
16
The single dipole model of the Earthrsquos magnetic field and the constant magnetic field vector corresponding to the circle equatorial orbit
The magnetic DSSC coordinate frames
17I3 The equations
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
2 2 2
2 1
0
T
x y zOx y z
T
orb orb
M M M
B m B m
oθ
θ
rbM m B
M
1 2
2 2
3 2
cos
cos
cos
OZ Ox
OZ Oy
OZ Oz
i k
j k
k k
2 2
2 1
2
0
Ap C B qr q Q
Bq A C pr p Q
C r B A pq M
orbQ B m
1
22 2 2 2 22
1 2 1 2 1 2
sin cos 1
2 2
T P
LI L l lT
A A A B C C
H H
cos sinP
P Q M Q
(6)
(5)
(4)
(3)
(2)
(1)
18I4 The integrals and solutions
2
2
2
1
2
23
x
y
z
K Ap
K KK Bq
K KK C r
K K
2
2
2
2 3
2
const
cos
z
z
L K C r
I I K
K C rL
K K K
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
2
2 2 22 2
1
2 2Ap Bq C r E C r TC
22 2 2 2 22 2A p B q C r K DT
2 1 2
22 21
2
22 2
Bq A C f q f q
C B C Ff q V E
A A B A A B
H B A B qf q V V
C A C
- AV Doroshin Exact Solutions in Attitude Dynamics of a Magnetic Dual-Spin Spacecraft and a Generalization of the Lagrange Top WSEAS Transactions on Systems Issue 10 Volume 12 (2013)
471-482
(11) (10)
(9)
(8) (7)
19I5 The analytical solution
The polhodes ellipsoid
2
2 2
22 2
2 1
1
1
q t H C A C x t SB A B
p t C B C x t FA A B
EAr t x t S t r t
A C C
2 20 0
2 20 0
sn
sn
i
i
R P c N t t I kx t e
R P c N t t I k
S E
The numerical integration (lines) and analytical (points) results
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075 q0=2 r0=583 [1s] K=50
[kgm2s] Q=100 [kgm2s2]
5
(13)
(12)
20I6 The analytical solution for Euler angles
orbB
K2K + ω timesK = mtimesK
K + ΩtimesK = 0
orbB
K 2Ω ω m
γ + Ωtimes γ = 0
1
2
3 2
t Ap t K
t Bq t K
C r t K
2cos
tg
t C r t K
Ap tt
Bq t
0
0
2 2
0 2 2 2 2
01
( ) ( )
( ) ( )
( )
t
t
t
t
Ap t Bq tt K dt
A p t B q t
t r t dtC
5
10 20 3003 052 08
The numerical integration (lines) and analytical (points) results for the directional cosines
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075
q0=2 r0=583 [1s] K=50 [km2s]
Q=100 [kgm2s2]
(19)
(20)
(18) (17)
(16)
(15)
(14)
21I7 Hamilton form of equations in the Andoyer-Deprit variables
(21)
(25)
(22)
(23)
(24)
1 C r
22
3 23
T T
T
L I Kl
I L I
K k K s K
K k
2
2
2
2 22
2 22
2
sin
cos
x
y
z
K Ap I L l
K Bq I L l
K C r L
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
22 2 2 2 22
1 2 1 2 1 2 2
sin cos 1
2 2
LI L l l LQ
A A A B C C I
H
22
(26)
Hamilton form of equations 2 2 2 1 1A B C A C
Equations (21) have heteroclinic solutions
Perturbations
0 0 L lM t f l t L t g t t dt
Melnikov function
(28)
The Melnikov function has the infinite number of simple roots This proves the fact of the motion chaotization at the presence of small harmonic perturbations
22 2 2 2
2 1
C B C EB
p t y t q t s k y t E r t y t t r tA A B B C C
0
sin cosN
n p n pn
Q t a n t b n t
22 2 2 2 2
20 0
1 2 1 2 1 2 2 20 1 0 1
sin cos 1
2 2
LI L l l L LQ Q Q t
A A A B C C I I
H H H H H
0 0 1 1
L L
L l L l
l l
L f l L gf f g g
l L l Ll f l L g
H H H H
0 0 00
cos sinN
ns n p n p
n
M t J a n t b n t
(27)
(26)
00 0 2
2
00 1 2 02
4 exp
exp 4
M aa E y t
ky t
Mt aE y a a a
k
23
2 l L I
I8 Numerical modeling Poincareacute sections mod 2 0pt
2 22 2 2 1 1 2 1 3 5
0 0 0 0
15 10 6 5 4[ ] 20 5 [ ] 075 [1 ] 1 5 20 [1]
) 5 004 ) 5 01 ) 10 01 ) 15 02
pA B C A C kg m I kg m s s a a a
a Q b Q c Q d Q
(a) (b)
(c) (d)
II The spider-type systems motion 24
m r K K K
1 2
3 4
5 6
4 2 m r
Ap p
Bq J I q I
Cr r
K K
ed
dt
Kω K M
12 56 34
34 12 56
56 34 12
ex
ey
ez
Ap I C B qr I q r M
Bq I A C pr I r p M
Cr I B A pq I p q M
4 2
4 2 4 2
iji j A A J I
B B J I C C J I
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i ex x
i e i ey y
i e i ez z
I p M M I p M M
I q M M I q M M
I r M M I r M M
(1)
(2)
(3)
(4)
II1 Angular momentum of the system in projections onto axes of the frame Oxyz
II2 The motion equations of the multirotor system
25
1 1
1 1
4 2
4 2 4 2
N Nij
il jl ll l
N N
l ll l
A A J NI
B B J NI C C J NI
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i el l lx l l lx
i e i el l ly l l ly
i e i el l lz l l lz
I p M M I p M M
I q M M I q M M
I r M M I r M M
0
1
2
3
cos 2
cos sin2
cos sin2
cos sin2
2 λ Θ λ
0
1
2
3
0
0
0
0
p q r
p r q
q r p
r q p
λ Θ
(4rsquo)
II3 The Euler parameters
(5)
26II4 The conjugate spinups and captures
Def1 Conjugate rotors are paired rotors located in the same layer on the opposite rays For example rotor 3N and rotor 4N are conjugate rotors (also rotor 12 and rotor 22 etc)
Def2 Conjugate spinup mean a process of spinning up conjugate rotors in opposite directions up to a desired value of relative angular velocity with the help of internal moments from main body Velocities of conjugate rotors will be equal in absolute value and opposite in sign
Def3 Rotor capture is an immediate deceleration of rotor relative angular velocity with the help of internal moment from the main body So rotor capture means an ldquoinstantaneous freezingrdquo of rotor with respect to the main body The capture can be performed with the help of gear meshing friction clutch or other methods
27
(6)
II6 Analytical solutions of motion equations
0e e ex y zM M M
A B C D
12 121
12 122
0
0
0
0
si
si
M if t tM
otherwise
M if t tM
otherwise
12 12 12sS M t I
1 12 2 12S S
1 1 12c c st t t
1 0
12
122
ISp
A IAS
A I
1 0 Conjugate spinup of rotors 1 2
Rotor 1 capture
Rotor 2 capture
2 2 1c c ct t t
1 2
121 2
0 0
c c
c c
t t tp IS
P t t tA I
Two serial captures of conjugate rotors bring to piecewise constant angular velocity of the main body
The main body performed the rotation about Ox axis by finite angle 12 2 1
c c
x
IS t t
A I
28
1 3 5 2 4 6
0 1 2 3
1 0
c c c c c c c cstart finish
c c c cstart start start start
t t t t t t t t
t t t t
0 1
2 3
2 2 2
cos sin2 2
sin sin2 2
c cstart start
c cstart start
c c c cstart finish finish start
t t t tPt t
t t t tQ Rt t
P Q R t t t T t t
1 2 t t t p P q Q r R
Letrsquos assume synchronically captures of coresponded conjugate rotors 1 2 3 4 5 6 and coincidence of the frame Oxyz initial position and the fixed frame OXYZ
Angular velocities between conjugate captures of rotors
Solutions of kinematic equations (5)
cos cos cosT
P Q R
T
e
The main body performed finite rotation about vector e by angle χ
(18)
(20)
(19)
(21)
29II7 Numerical simulation of reorientation process
const 0 1 135 246
i s cj jj j j
i s cj jj j j
jj
M M H t H t t H t t
M M H t H t t H t t
M j j
Two sets of results of numerical simulation
1 4 5(0) (0) (0) 0 (0) 100 1 s ω
ν = 300 Nms
H(t) is Heaviside function
FigA - zero value of angular momentum and different inertia moments of main body
Fig A Fig B
Fig4 - reorientation process at nonzero system angular momentum
30
__________________________________________________________
The main properties of the attitude stabilization and control of SC (and multirotor systems) have been examined
Research into attitude motion of the one-body-SC dual-spin SC and spider-type-SC is very complicated
Nontrivial and chaotic modes are possible in the SC attitude motion
Conclusion
- Slide 1
- Outline
- Part 1 - Introduction to Attitude Dynamics and Control
- Slide 4
- Spin stabilization
- Spin Stabilization Dual-Spin Spacecraft
- Spin Stabilization Dual-Spin Spacecraft (2)
- Spin Stabilization Dual-Spin Spacecraft (3)
- Spin Stabilization Dual-Spin Spacecraft (4)
- Gravity Gradient Stabilization
- Magnetic Stabilization
- Aerodynamic Stabilization
- Actuators
- Actuators (2)
- Actuators (3)
- Main Equations of Angular Motion of Rigid Body (Attitude Motion
- Main Properties of the Free Angular Motion of Rigid Body (Attit
- Main Properties of the Free Angular Motion of Rigid Body (Attit (2)
- Part 2 ndash Research Results
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
-
Part 1 - Introduction to Attitude
Dynamics and Control
Most of the spacecraft have instruments or antennas that must be pointed
in specific directions
ndash The Hubble must point its main telescope
ndash Communications satellites must point their antennas
The orientation of the spacecraft in the space is called its attitude
To control the attitude the spacecraft operators must have the ability to
ndash Determine the current attitude (sensorshellip)
ndash Determine the error between the current and desired attitudes
ndash Apply torques to remove the error (with the help of actuatorshellip)
2
The Spacecraft Attitude Stabilizationbull mdash Spin Stabilization methodsbull mdash Gravity Gradient Stabilization methodsbull mdash Magnetic Stabilization methodsbull mdash Aerodynamic Stabilization methods
Actuatorsbull mdash Reaction Wheel Assemblies (RWAs)bull mdash Control Moment Gyros (CMGs)bull mdash Thrusters
3
Spin stabilization4
The TopSpin stabilized spacecraft
Spin-stabilization is a method of SC stabilizing in a fixed orientation using rotational motion around SC axis (usually symmetry axis ) ndash ldquothe gyroscopic effectrdquo
Spin StabilizationDual-Spin Spacecraft
4
TACSAT I was the largest and most powerful communications satellite at the time when it was launched into synchronous orbit by a Titan IIIC booster 9 February 1969 from Cape Canaveral Florida
TACSAT I The antenna is the platform and is intended to point continuously at the Earth spinning at one evolution per orbit The cylindrical body is the rotor providing gyroscopic stability through its 60 RPM spin
Spin StabilizationDual-Spin Spacecraft
4
The dual-spin construction-scheme is quite useful in the practice during all history of space flights realization and it is possible to present some examples of the DSSC which was used in real space-programs (most of them are communications satellites and observing geostationary satellites)
- This is long-continued and well successful project ldquoIntelsatrdquo (the Intelsat II series of satellites first launched in 1966) including 8th generation of geostationary communications satellites and Intelsat VI (1991) designed and built by Hughes Aircraft Company - The ldquoMeteosatrdquo-project by European Space Research Organization (initiated with Meteosat-1 in 1977 and operated until 2007 with
Meteosat-7) also used dual-spin configuration spacecraft - Spin-stabilized spacecraft with mechanically despun antennas was applied in the framework of GEOTAIL (a collaborative mission
of Japan JAXAISAS and NASA within the program ldquoInternational Solar-Terrestrial Physicsrdquo) launched in 1992 the GEOTAIL spacecraft and its payload continue to operate in 2013
- Analogously the construction scheme with despun antenna was selected for Chinese communications satellites DFH-2 (STW-3 1988 STW-4 1988 STW-55 1990)
- Well-known Galileo missionrsquos spacecraft (the fifth spacecraft to visit Jupiter launched on October 19 1989) was designed by dual-spin scheme
- Of course we need to indicate one of the worlds most-purchased commercial communications satellite models such as Hughes Boeing HS-376 BSS-376 (for example Satellite Business Systems with projects SBS 1 2 3 4 5 6 HGS 5 etc) they have spun section containing propulsion system solar drums and despun section containing the satellites communications payload and antennas
- Also very popular and versatile dual-spin models are Hughes HS-381 (Leasat project) HS-389 (Intelsat project) HS-393 (JCSat project)
The DSSC usually is used for the attitude stabilization by partial twist method only one of the DSSCs coaxial bodies (the laquorotorraquo-body) has rotation at the laquoquiescenceraquo of the second body (the laquoplatformraquo-body) ndash it allows to place into the laquoplatformraquo-body some exploratory equipment and to perform of space-mission tests without rotational disturbances
Spin StabilizationDual-Spin Spacecraft
4
HS 376Class Communications Nation USA
Mass 654 kg at beginning-of-life in geosynchronous orbit
Spin stabilized at 50 rpm by 4 hydrazine thrusters with 136 kg propellant Star 30 apogee kick motor Solar cells mounted on outside of cylindrical satellite body provide 990 W of power and recharge two NiCd batteries 24 + 6 backup 9 W transmission beams
HS 376 Chronology- 15 November 1980 SBS 1 Program- hellip- 22 November 1998 BONUM-1 Program
Spin StabilizationDual-Spin Spacecraft
4
Hughes HS-389
Intelsat-6 [Boeing] SDS-2 [NRO]
Ordered Date
Intelsat 601 1982 29101991
Intelsat 602 1982 27101989
Intelsat 603 1982 14031990
Intelsat 604 1982 23061990
Intelsat 605 1982 14081991
SDS-2 1 08081989
SDS-2 2 15111990
SDS-2 3 02121992
SDS-2 4 03071996
Gravity Gradient Stabilization 5
UniCubeSat-GG is the first CubeSat mission of GAUSS (Gruppo di Astrodinamica dell Universita degli Studi ldquola Sapienzardquo) at the University of Rome (Universita di Roma ldquoLa Sapienzardquo Scuola di Ingegneria Aerospaziale) Italy
The Gravity-gradient stabilization is a method of SC stabilizing in a fixed orientation using only the orbited bodys mass distribution and the Earths gravitational field
SC is placed along the radius-vector of the Earth
Tether-satellitesPhysical pendulums
Magnetic Stabilization 6
Magnetic stabilization is a method of SC stabilizing using geomagnetic field of the Earth
SC is positioned along the magnetic lines of the geomagnetic field (ldquomagnetic compassrdquo)
One of Four Alinco-5 Permanent Magnet sets on board KySat-1
KySat-1 Passive Magnetic Stabilization System is used for antenna orientation and coarse camera pointing
KySat-1 the first satellite project by Kentucky Space is a 1-U CubeSat scheduled to launch in 2010 on a NASA mission
Aerodynamic Stabilization 7
The Aerodynamic stabilization is a method of SC stabilizing using aerodynamic force in rarefied atmosphere of low earth orbit
SC is positioned along the orbital velocity vector
Aerodynamically Stable CubeSat Design Concept
ldquogo like an arrow helliprdquo
SC with tail unit
Actuators 8Reaction Wheel Assemblies (RWAs)
RWAs are particularly useful when the spacecraft must be rotated by very small amounts such as keeping a telescope pointed at a star
This is accomplished by equipping the spacecraft with an electric motor attached to a flywheel which when rotated increasingly fast causes the spacecraft to spin the other way in a proportional amount by conservation of angular momentum
Actuators 9Control Moment Gyros (CMGs)
A CMG consists of a spinning rotor and one or more motorized gimbals that tilt the rotorrsquos angular momentum As the rotor tilts the changing angular momentum causes a gyroscopic torque that rotates the spacecraft
Microsatellite with four control moment gyroscopes
Actuators 10Thrusters
A thruster is a small propulsive device used by spacecraft for attitude control in the reaction control system or long-duration low-thrust acceleration
Liquefied gases in high-pressure balloons
Main Equations of Angular Motion of Rigid Body(Attitude Motion of SC)
11
Euler dynamical equations
Euler kinematical equations
The study of the angular motion of the SC attitude dynamics is one of the main problems of rigid body systems dynamics in the classical mechanics
And vice versa
Tasks of analysis and synthesis of the rigid bodiesrsquo motion have important applications in the space-flight dynamics
Main Properties of the Free Angular Motion of Rigid Body(Attitude Motion of SC)
12
Louis Poinsot interpreacutetation
Inertia tensor with polhodes
--- notation by CDHall
Main Properties of the Free Angular Motion of Rigid Body(Attitude Motion of SC)
12
If we consider rigid body angular motion on the base of Hamilton dynamics than for rigid body motion we take pendulum phase structure
x=tetta (nutation) and
y = impulse (tetta) ~ d(tetta)dt
Pendulum phase space
Part 2 ndash Research Results
1 The magnetized dual-spin spacecraft attitude motion
2 The regular and chaotic dynamics of dual-spin spacecraft
3 The multi-rotor system and multi-spin spacecraft dynamics
13
14
Letrsquos consider an angular motion (about point O) of spider-type multiple rotor rigid bodies systems and
coaxial bodies systems
Mechanical models of multiple-rotor systems
Coaxial bodies system(dual-spin spacecraft)
Multirotor spiders(gyrostat-spacecrafts)
Number of rotors = N
Number of rotors = 6 Number of rotors = 1
1cos sin
cos
sin cos
sincos sin
cos
p q
p q
r p q
(1)
(2)
15
I1 The angular motion general equations
I The coaxial bodies system motion
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
cos sinP
P Q M Q
The coaxial top
I2 The angular motion equations of the magnetic DSSC and the coaxial Lagrange top
16
The single dipole model of the Earthrsquos magnetic field and the constant magnetic field vector corresponding to the circle equatorial orbit
The magnetic DSSC coordinate frames
17I3 The equations
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
2 2 2
2 1
0
T
x y zOx y z
T
orb orb
M M M
B m B m
oθ
θ
rbM m B
M
1 2
2 2
3 2
cos
cos
cos
OZ Ox
OZ Oy
OZ Oz
i k
j k
k k
2 2
2 1
2
0
Ap C B qr q Q
Bq A C pr p Q
C r B A pq M
orbQ B m
1
22 2 2 2 22
1 2 1 2 1 2
sin cos 1
2 2
T P
LI L l lT
A A A B C C
H H
cos sinP
P Q M Q
(6)
(5)
(4)
(3)
(2)
(1)
18I4 The integrals and solutions
2
2
2
1
2
23
x
y
z
K Ap
K KK Bq
K KK C r
K K
2
2
2
2 3
2
const
cos
z
z
L K C r
I I K
K C rL
K K K
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
2
2 2 22 2
1
2 2Ap Bq C r E C r TC
22 2 2 2 22 2A p B q C r K DT
2 1 2
22 21
2
22 2
Bq A C f q f q
C B C Ff q V E
A A B A A B
H B A B qf q V V
C A C
- AV Doroshin Exact Solutions in Attitude Dynamics of a Magnetic Dual-Spin Spacecraft and a Generalization of the Lagrange Top WSEAS Transactions on Systems Issue 10 Volume 12 (2013)
471-482
(11) (10)
(9)
(8) (7)
19I5 The analytical solution
The polhodes ellipsoid
2
2 2
22 2
2 1
1
1
q t H C A C x t SB A B
p t C B C x t FA A B
EAr t x t S t r t
A C C
2 20 0
2 20 0
sn
sn
i
i
R P c N t t I kx t e
R P c N t t I k
S E
The numerical integration (lines) and analytical (points) results
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075 q0=2 r0=583 [1s] K=50
[kgm2s] Q=100 [kgm2s2]
5
(13)
(12)
20I6 The analytical solution for Euler angles
orbB
K2K + ω timesK = mtimesK
K + ΩtimesK = 0
orbB
K 2Ω ω m
γ + Ωtimes γ = 0
1
2
3 2
t Ap t K
t Bq t K
C r t K
2cos
tg
t C r t K
Ap tt
Bq t
0
0
2 2
0 2 2 2 2
01
( ) ( )
( ) ( )
( )
t
t
t
t
Ap t Bq tt K dt
A p t B q t
t r t dtC
5
10 20 3003 052 08
The numerical integration (lines) and analytical (points) results for the directional cosines
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075
q0=2 r0=583 [1s] K=50 [km2s]
Q=100 [kgm2s2]
(19)
(20)
(18) (17)
(16)
(15)
(14)
21I7 Hamilton form of equations in the Andoyer-Deprit variables
(21)
(25)
(22)
(23)
(24)
1 C r
22
3 23
T T
T
L I Kl
I L I
K k K s K
K k
2
2
2
2 22
2 22
2
sin
cos
x
y
z
K Ap I L l
K Bq I L l
K C r L
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
22 2 2 2 22
1 2 1 2 1 2 2
sin cos 1
2 2
LI L l l LQ
A A A B C C I
H
22
(26)
Hamilton form of equations 2 2 2 1 1A B C A C
Equations (21) have heteroclinic solutions
Perturbations
0 0 L lM t f l t L t g t t dt
Melnikov function
(28)
The Melnikov function has the infinite number of simple roots This proves the fact of the motion chaotization at the presence of small harmonic perturbations
22 2 2 2
2 1
C B C EB
p t y t q t s k y t E r t y t t r tA A B B C C
0
sin cosN
n p n pn
Q t a n t b n t
22 2 2 2 2
20 0
1 2 1 2 1 2 2 20 1 0 1
sin cos 1
2 2
LI L l l L LQ Q Q t
A A A B C C I I
H H H H H
0 0 1 1
L L
L l L l
l l
L f l L gf f g g
l L l Ll f l L g
H H H H
0 0 00
cos sinN
ns n p n p
n
M t J a n t b n t
(27)
(26)
00 0 2
2
00 1 2 02
4 exp
exp 4
M aa E y t
ky t
Mt aE y a a a
k
23
2 l L I
I8 Numerical modeling Poincareacute sections mod 2 0pt
2 22 2 2 1 1 2 1 3 5
0 0 0 0
15 10 6 5 4[ ] 20 5 [ ] 075 [1 ] 1 5 20 [1]
) 5 004 ) 5 01 ) 10 01 ) 15 02
pA B C A C kg m I kg m s s a a a
a Q b Q c Q d Q
(a) (b)
(c) (d)
II The spider-type systems motion 24
m r K K K
1 2
3 4
5 6
4 2 m r
Ap p
Bq J I q I
Cr r
K K
ed
dt
Kω K M
12 56 34
34 12 56
56 34 12
ex
ey
ez
Ap I C B qr I q r M
Bq I A C pr I r p M
Cr I B A pq I p q M
4 2
4 2 4 2
iji j A A J I
B B J I C C J I
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i ex x
i e i ey y
i e i ez z
I p M M I p M M
I q M M I q M M
I r M M I r M M
(1)
(2)
(3)
(4)
II1 Angular momentum of the system in projections onto axes of the frame Oxyz
II2 The motion equations of the multirotor system
25
1 1
1 1
4 2
4 2 4 2
N Nij
il jl ll l
N N
l ll l
A A J NI
B B J NI C C J NI
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i el l lx l l lx
i e i el l ly l l ly
i e i el l lz l l lz
I p M M I p M M
I q M M I q M M
I r M M I r M M
0
1
2
3
cos 2
cos sin2
cos sin2
cos sin2
2 λ Θ λ
0
1
2
3
0
0
0
0
p q r
p r q
q r p
r q p
λ Θ
(4rsquo)
II3 The Euler parameters
(5)
26II4 The conjugate spinups and captures
Def1 Conjugate rotors are paired rotors located in the same layer on the opposite rays For example rotor 3N and rotor 4N are conjugate rotors (also rotor 12 and rotor 22 etc)
Def2 Conjugate spinup mean a process of spinning up conjugate rotors in opposite directions up to a desired value of relative angular velocity with the help of internal moments from main body Velocities of conjugate rotors will be equal in absolute value and opposite in sign
Def3 Rotor capture is an immediate deceleration of rotor relative angular velocity with the help of internal moment from the main body So rotor capture means an ldquoinstantaneous freezingrdquo of rotor with respect to the main body The capture can be performed with the help of gear meshing friction clutch or other methods
27
(6)
II6 Analytical solutions of motion equations
0e e ex y zM M M
A B C D
12 121
12 122
0
0
0
0
si
si
M if t tM
otherwise
M if t tM
otherwise
12 12 12sS M t I
1 12 2 12S S
1 1 12c c st t t
1 0
12
122
ISp
A IAS
A I
1 0 Conjugate spinup of rotors 1 2
Rotor 1 capture
Rotor 2 capture
2 2 1c c ct t t
1 2
121 2
0 0
c c
c c
t t tp IS
P t t tA I
Two serial captures of conjugate rotors bring to piecewise constant angular velocity of the main body
The main body performed the rotation about Ox axis by finite angle 12 2 1
c c
x
IS t t
A I
28
1 3 5 2 4 6
0 1 2 3
1 0
c c c c c c c cstart finish
c c c cstart start start start
t t t t t t t t
t t t t
0 1
2 3
2 2 2
cos sin2 2
sin sin2 2
c cstart start
c cstart start
c c c cstart finish finish start
t t t tPt t
t t t tQ Rt t
P Q R t t t T t t
1 2 t t t p P q Q r R
Letrsquos assume synchronically captures of coresponded conjugate rotors 1 2 3 4 5 6 and coincidence of the frame Oxyz initial position and the fixed frame OXYZ
Angular velocities between conjugate captures of rotors
Solutions of kinematic equations (5)
cos cos cosT
P Q R
T
e
The main body performed finite rotation about vector e by angle χ
(18)
(20)
(19)
(21)
29II7 Numerical simulation of reorientation process
const 0 1 135 246
i s cj jj j j
i s cj jj j j
jj
M M H t H t t H t t
M M H t H t t H t t
M j j
Two sets of results of numerical simulation
1 4 5(0) (0) (0) 0 (0) 100 1 s ω
ν = 300 Nms
H(t) is Heaviside function
FigA - zero value of angular momentum and different inertia moments of main body
Fig A Fig B
Fig4 - reorientation process at nonzero system angular momentum
30
__________________________________________________________
The main properties of the attitude stabilization and control of SC (and multirotor systems) have been examined
Research into attitude motion of the one-body-SC dual-spin SC and spider-type-SC is very complicated
Nontrivial and chaotic modes are possible in the SC attitude motion
Conclusion
- Slide 1
- Outline
- Part 1 - Introduction to Attitude Dynamics and Control
- Slide 4
- Spin stabilization
- Spin Stabilization Dual-Spin Spacecraft
- Spin Stabilization Dual-Spin Spacecraft (2)
- Spin Stabilization Dual-Spin Spacecraft (3)
- Spin Stabilization Dual-Spin Spacecraft (4)
- Gravity Gradient Stabilization
- Magnetic Stabilization
- Aerodynamic Stabilization
- Actuators
- Actuators (2)
- Actuators (3)
- Main Equations of Angular Motion of Rigid Body (Attitude Motion
- Main Properties of the Free Angular Motion of Rigid Body (Attit
- Main Properties of the Free Angular Motion of Rigid Body (Attit (2)
- Part 2 ndash Research Results
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
-
The Spacecraft Attitude Stabilizationbull mdash Spin Stabilization methodsbull mdash Gravity Gradient Stabilization methodsbull mdash Magnetic Stabilization methodsbull mdash Aerodynamic Stabilization methods
Actuatorsbull mdash Reaction Wheel Assemblies (RWAs)bull mdash Control Moment Gyros (CMGs)bull mdash Thrusters
3
Spin stabilization4
The TopSpin stabilized spacecraft
Spin-stabilization is a method of SC stabilizing in a fixed orientation using rotational motion around SC axis (usually symmetry axis ) ndash ldquothe gyroscopic effectrdquo
Spin StabilizationDual-Spin Spacecraft
4
TACSAT I was the largest and most powerful communications satellite at the time when it was launched into synchronous orbit by a Titan IIIC booster 9 February 1969 from Cape Canaveral Florida
TACSAT I The antenna is the platform and is intended to point continuously at the Earth spinning at one evolution per orbit The cylindrical body is the rotor providing gyroscopic stability through its 60 RPM spin
Spin StabilizationDual-Spin Spacecraft
4
The dual-spin construction-scheme is quite useful in the practice during all history of space flights realization and it is possible to present some examples of the DSSC which was used in real space-programs (most of them are communications satellites and observing geostationary satellites)
- This is long-continued and well successful project ldquoIntelsatrdquo (the Intelsat II series of satellites first launched in 1966) including 8th generation of geostationary communications satellites and Intelsat VI (1991) designed and built by Hughes Aircraft Company - The ldquoMeteosatrdquo-project by European Space Research Organization (initiated with Meteosat-1 in 1977 and operated until 2007 with
Meteosat-7) also used dual-spin configuration spacecraft - Spin-stabilized spacecraft with mechanically despun antennas was applied in the framework of GEOTAIL (a collaborative mission
of Japan JAXAISAS and NASA within the program ldquoInternational Solar-Terrestrial Physicsrdquo) launched in 1992 the GEOTAIL spacecraft and its payload continue to operate in 2013
- Analogously the construction scheme with despun antenna was selected for Chinese communications satellites DFH-2 (STW-3 1988 STW-4 1988 STW-55 1990)
- Well-known Galileo missionrsquos spacecraft (the fifth spacecraft to visit Jupiter launched on October 19 1989) was designed by dual-spin scheme
- Of course we need to indicate one of the worlds most-purchased commercial communications satellite models such as Hughes Boeing HS-376 BSS-376 (for example Satellite Business Systems with projects SBS 1 2 3 4 5 6 HGS 5 etc) they have spun section containing propulsion system solar drums and despun section containing the satellites communications payload and antennas
- Also very popular and versatile dual-spin models are Hughes HS-381 (Leasat project) HS-389 (Intelsat project) HS-393 (JCSat project)
The DSSC usually is used for the attitude stabilization by partial twist method only one of the DSSCs coaxial bodies (the laquorotorraquo-body) has rotation at the laquoquiescenceraquo of the second body (the laquoplatformraquo-body) ndash it allows to place into the laquoplatformraquo-body some exploratory equipment and to perform of space-mission tests without rotational disturbances
Spin StabilizationDual-Spin Spacecraft
4
HS 376Class Communications Nation USA
Mass 654 kg at beginning-of-life in geosynchronous orbit
Spin stabilized at 50 rpm by 4 hydrazine thrusters with 136 kg propellant Star 30 apogee kick motor Solar cells mounted on outside of cylindrical satellite body provide 990 W of power and recharge two NiCd batteries 24 + 6 backup 9 W transmission beams
HS 376 Chronology- 15 November 1980 SBS 1 Program- hellip- 22 November 1998 BONUM-1 Program
Spin StabilizationDual-Spin Spacecraft
4
Hughes HS-389
Intelsat-6 [Boeing] SDS-2 [NRO]
Ordered Date
Intelsat 601 1982 29101991
Intelsat 602 1982 27101989
Intelsat 603 1982 14031990
Intelsat 604 1982 23061990
Intelsat 605 1982 14081991
SDS-2 1 08081989
SDS-2 2 15111990
SDS-2 3 02121992
SDS-2 4 03071996
Gravity Gradient Stabilization 5
UniCubeSat-GG is the first CubeSat mission of GAUSS (Gruppo di Astrodinamica dell Universita degli Studi ldquola Sapienzardquo) at the University of Rome (Universita di Roma ldquoLa Sapienzardquo Scuola di Ingegneria Aerospaziale) Italy
The Gravity-gradient stabilization is a method of SC stabilizing in a fixed orientation using only the orbited bodys mass distribution and the Earths gravitational field
SC is placed along the radius-vector of the Earth
Tether-satellitesPhysical pendulums
Magnetic Stabilization 6
Magnetic stabilization is a method of SC stabilizing using geomagnetic field of the Earth
SC is positioned along the magnetic lines of the geomagnetic field (ldquomagnetic compassrdquo)
One of Four Alinco-5 Permanent Magnet sets on board KySat-1
KySat-1 Passive Magnetic Stabilization System is used for antenna orientation and coarse camera pointing
KySat-1 the first satellite project by Kentucky Space is a 1-U CubeSat scheduled to launch in 2010 on a NASA mission
Aerodynamic Stabilization 7
The Aerodynamic stabilization is a method of SC stabilizing using aerodynamic force in rarefied atmosphere of low earth orbit
SC is positioned along the orbital velocity vector
Aerodynamically Stable CubeSat Design Concept
ldquogo like an arrow helliprdquo
SC with tail unit
Actuators 8Reaction Wheel Assemblies (RWAs)
RWAs are particularly useful when the spacecraft must be rotated by very small amounts such as keeping a telescope pointed at a star
This is accomplished by equipping the spacecraft with an electric motor attached to a flywheel which when rotated increasingly fast causes the spacecraft to spin the other way in a proportional amount by conservation of angular momentum
Actuators 9Control Moment Gyros (CMGs)
A CMG consists of a spinning rotor and one or more motorized gimbals that tilt the rotorrsquos angular momentum As the rotor tilts the changing angular momentum causes a gyroscopic torque that rotates the spacecraft
Microsatellite with four control moment gyroscopes
Actuators 10Thrusters
A thruster is a small propulsive device used by spacecraft for attitude control in the reaction control system or long-duration low-thrust acceleration
Liquefied gases in high-pressure balloons
Main Equations of Angular Motion of Rigid Body(Attitude Motion of SC)
11
Euler dynamical equations
Euler kinematical equations
The study of the angular motion of the SC attitude dynamics is one of the main problems of rigid body systems dynamics in the classical mechanics
And vice versa
Tasks of analysis and synthesis of the rigid bodiesrsquo motion have important applications in the space-flight dynamics
Main Properties of the Free Angular Motion of Rigid Body(Attitude Motion of SC)
12
Louis Poinsot interpreacutetation
Inertia tensor with polhodes
--- notation by CDHall
Main Properties of the Free Angular Motion of Rigid Body(Attitude Motion of SC)
12
If we consider rigid body angular motion on the base of Hamilton dynamics than for rigid body motion we take pendulum phase structure
x=tetta (nutation) and
y = impulse (tetta) ~ d(tetta)dt
Pendulum phase space
Part 2 ndash Research Results
1 The magnetized dual-spin spacecraft attitude motion
2 The regular and chaotic dynamics of dual-spin spacecraft
3 The multi-rotor system and multi-spin spacecraft dynamics
13
14
Letrsquos consider an angular motion (about point O) of spider-type multiple rotor rigid bodies systems and
coaxial bodies systems
Mechanical models of multiple-rotor systems
Coaxial bodies system(dual-spin spacecraft)
Multirotor spiders(gyrostat-spacecrafts)
Number of rotors = N
Number of rotors = 6 Number of rotors = 1
1cos sin
cos
sin cos
sincos sin
cos
p q
p q
r p q
(1)
(2)
15
I1 The angular motion general equations
I The coaxial bodies system motion
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
cos sinP
P Q M Q
The coaxial top
I2 The angular motion equations of the magnetic DSSC and the coaxial Lagrange top
16
The single dipole model of the Earthrsquos magnetic field and the constant magnetic field vector corresponding to the circle equatorial orbit
The magnetic DSSC coordinate frames
17I3 The equations
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
2 2 2
2 1
0
T
x y zOx y z
T
orb orb
M M M
B m B m
oθ
θ
rbM m B
M
1 2
2 2
3 2
cos
cos
cos
OZ Ox
OZ Oy
OZ Oz
i k
j k
k k
2 2
2 1
2
0
Ap C B qr q Q
Bq A C pr p Q
C r B A pq M
orbQ B m
1
22 2 2 2 22
1 2 1 2 1 2
sin cos 1
2 2
T P
LI L l lT
A A A B C C
H H
cos sinP
P Q M Q
(6)
(5)
(4)
(3)
(2)
(1)
18I4 The integrals and solutions
2
2
2
1
2
23
x
y
z
K Ap
K KK Bq
K KK C r
K K
2
2
2
2 3
2
const
cos
z
z
L K C r
I I K
K C rL
K K K
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
2
2 2 22 2
1
2 2Ap Bq C r E C r TC
22 2 2 2 22 2A p B q C r K DT
2 1 2
22 21
2
22 2
Bq A C f q f q
C B C Ff q V E
A A B A A B
H B A B qf q V V
C A C
- AV Doroshin Exact Solutions in Attitude Dynamics of a Magnetic Dual-Spin Spacecraft and a Generalization of the Lagrange Top WSEAS Transactions on Systems Issue 10 Volume 12 (2013)
471-482
(11) (10)
(9)
(8) (7)
19I5 The analytical solution
The polhodes ellipsoid
2
2 2
22 2
2 1
1
1
q t H C A C x t SB A B
p t C B C x t FA A B
EAr t x t S t r t
A C C
2 20 0
2 20 0
sn
sn
i
i
R P c N t t I kx t e
R P c N t t I k
S E
The numerical integration (lines) and analytical (points) results
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075 q0=2 r0=583 [1s] K=50
[kgm2s] Q=100 [kgm2s2]
5
(13)
(12)
20I6 The analytical solution for Euler angles
orbB
K2K + ω timesK = mtimesK
K + ΩtimesK = 0
orbB
K 2Ω ω m
γ + Ωtimes γ = 0
1
2
3 2
t Ap t K
t Bq t K
C r t K
2cos
tg
t C r t K
Ap tt
Bq t
0
0
2 2
0 2 2 2 2
01
( ) ( )
( ) ( )
( )
t
t
t
t
Ap t Bq tt K dt
A p t B q t
t r t dtC
5
10 20 3003 052 08
The numerical integration (lines) and analytical (points) results for the directional cosines
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075
q0=2 r0=583 [1s] K=50 [km2s]
Q=100 [kgm2s2]
(19)
(20)
(18) (17)
(16)
(15)
(14)
21I7 Hamilton form of equations in the Andoyer-Deprit variables
(21)
(25)
(22)
(23)
(24)
1 C r
22
3 23
T T
T
L I Kl
I L I
K k K s K
K k
2
2
2
2 22
2 22
2
sin
cos
x
y
z
K Ap I L l
K Bq I L l
K C r L
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
22 2 2 2 22
1 2 1 2 1 2 2
sin cos 1
2 2
LI L l l LQ
A A A B C C I
H
22
(26)
Hamilton form of equations 2 2 2 1 1A B C A C
Equations (21) have heteroclinic solutions
Perturbations
0 0 L lM t f l t L t g t t dt
Melnikov function
(28)
The Melnikov function has the infinite number of simple roots This proves the fact of the motion chaotization at the presence of small harmonic perturbations
22 2 2 2
2 1
C B C EB
p t y t q t s k y t E r t y t t r tA A B B C C
0
sin cosN
n p n pn
Q t a n t b n t
22 2 2 2 2
20 0
1 2 1 2 1 2 2 20 1 0 1
sin cos 1
2 2
LI L l l L LQ Q Q t
A A A B C C I I
H H H H H
0 0 1 1
L L
L l L l
l l
L f l L gf f g g
l L l Ll f l L g
H H H H
0 0 00
cos sinN
ns n p n p
n
M t J a n t b n t
(27)
(26)
00 0 2
2
00 1 2 02
4 exp
exp 4
M aa E y t
ky t
Mt aE y a a a
k
23
2 l L I
I8 Numerical modeling Poincareacute sections mod 2 0pt
2 22 2 2 1 1 2 1 3 5
0 0 0 0
15 10 6 5 4[ ] 20 5 [ ] 075 [1 ] 1 5 20 [1]
) 5 004 ) 5 01 ) 10 01 ) 15 02
pA B C A C kg m I kg m s s a a a
a Q b Q c Q d Q
(a) (b)
(c) (d)
II The spider-type systems motion 24
m r K K K
1 2
3 4
5 6
4 2 m r
Ap p
Bq J I q I
Cr r
K K
ed
dt
Kω K M
12 56 34
34 12 56
56 34 12
ex
ey
ez
Ap I C B qr I q r M
Bq I A C pr I r p M
Cr I B A pq I p q M
4 2
4 2 4 2
iji j A A J I
B B J I C C J I
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i ex x
i e i ey y
i e i ez z
I p M M I p M M
I q M M I q M M
I r M M I r M M
(1)
(2)
(3)
(4)
II1 Angular momentum of the system in projections onto axes of the frame Oxyz
II2 The motion equations of the multirotor system
25
1 1
1 1
4 2
4 2 4 2
N Nij
il jl ll l
N N
l ll l
A A J NI
B B J NI C C J NI
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i el l lx l l lx
i e i el l ly l l ly
i e i el l lz l l lz
I p M M I p M M
I q M M I q M M
I r M M I r M M
0
1
2
3
cos 2
cos sin2
cos sin2
cos sin2
2 λ Θ λ
0
1
2
3
0
0
0
0
p q r
p r q
q r p
r q p
λ Θ
(4rsquo)
II3 The Euler parameters
(5)
26II4 The conjugate spinups and captures
Def1 Conjugate rotors are paired rotors located in the same layer on the opposite rays For example rotor 3N and rotor 4N are conjugate rotors (also rotor 12 and rotor 22 etc)
Def2 Conjugate spinup mean a process of spinning up conjugate rotors in opposite directions up to a desired value of relative angular velocity with the help of internal moments from main body Velocities of conjugate rotors will be equal in absolute value and opposite in sign
Def3 Rotor capture is an immediate deceleration of rotor relative angular velocity with the help of internal moment from the main body So rotor capture means an ldquoinstantaneous freezingrdquo of rotor with respect to the main body The capture can be performed with the help of gear meshing friction clutch or other methods
27
(6)
II6 Analytical solutions of motion equations
0e e ex y zM M M
A B C D
12 121
12 122
0
0
0
0
si
si
M if t tM
otherwise
M if t tM
otherwise
12 12 12sS M t I
1 12 2 12S S
1 1 12c c st t t
1 0
12
122
ISp
A IAS
A I
1 0 Conjugate spinup of rotors 1 2
Rotor 1 capture
Rotor 2 capture
2 2 1c c ct t t
1 2
121 2
0 0
c c
c c
t t tp IS
P t t tA I
Two serial captures of conjugate rotors bring to piecewise constant angular velocity of the main body
The main body performed the rotation about Ox axis by finite angle 12 2 1
c c
x
IS t t
A I
28
1 3 5 2 4 6
0 1 2 3
1 0
c c c c c c c cstart finish
c c c cstart start start start
t t t t t t t t
t t t t
0 1
2 3
2 2 2
cos sin2 2
sin sin2 2
c cstart start
c cstart start
c c c cstart finish finish start
t t t tPt t
t t t tQ Rt t
P Q R t t t T t t
1 2 t t t p P q Q r R
Letrsquos assume synchronically captures of coresponded conjugate rotors 1 2 3 4 5 6 and coincidence of the frame Oxyz initial position and the fixed frame OXYZ
Angular velocities between conjugate captures of rotors
Solutions of kinematic equations (5)
cos cos cosT
P Q R
T
e
The main body performed finite rotation about vector e by angle χ
(18)
(20)
(19)
(21)
29II7 Numerical simulation of reorientation process
const 0 1 135 246
i s cj jj j j
i s cj jj j j
jj
M M H t H t t H t t
M M H t H t t H t t
M j j
Two sets of results of numerical simulation
1 4 5(0) (0) (0) 0 (0) 100 1 s ω
ν = 300 Nms
H(t) is Heaviside function
FigA - zero value of angular momentum and different inertia moments of main body
Fig A Fig B
Fig4 - reorientation process at nonzero system angular momentum
30
__________________________________________________________
The main properties of the attitude stabilization and control of SC (and multirotor systems) have been examined
Research into attitude motion of the one-body-SC dual-spin SC and spider-type-SC is very complicated
Nontrivial and chaotic modes are possible in the SC attitude motion
Conclusion
- Slide 1
- Outline
- Part 1 - Introduction to Attitude Dynamics and Control
- Slide 4
- Spin stabilization
- Spin Stabilization Dual-Spin Spacecraft
- Spin Stabilization Dual-Spin Spacecraft (2)
- Spin Stabilization Dual-Spin Spacecraft (3)
- Spin Stabilization Dual-Spin Spacecraft (4)
- Gravity Gradient Stabilization
- Magnetic Stabilization
- Aerodynamic Stabilization
- Actuators
- Actuators (2)
- Actuators (3)
- Main Equations of Angular Motion of Rigid Body (Attitude Motion
- Main Properties of the Free Angular Motion of Rigid Body (Attit
- Main Properties of the Free Angular Motion of Rigid Body (Attit (2)
- Part 2 ndash Research Results
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
-
Spin stabilization4
The TopSpin stabilized spacecraft
Spin-stabilization is a method of SC stabilizing in a fixed orientation using rotational motion around SC axis (usually symmetry axis ) ndash ldquothe gyroscopic effectrdquo
Spin StabilizationDual-Spin Spacecraft
4
TACSAT I was the largest and most powerful communications satellite at the time when it was launched into synchronous orbit by a Titan IIIC booster 9 February 1969 from Cape Canaveral Florida
TACSAT I The antenna is the platform and is intended to point continuously at the Earth spinning at one evolution per orbit The cylindrical body is the rotor providing gyroscopic stability through its 60 RPM spin
Spin StabilizationDual-Spin Spacecraft
4
The dual-spin construction-scheme is quite useful in the practice during all history of space flights realization and it is possible to present some examples of the DSSC which was used in real space-programs (most of them are communications satellites and observing geostationary satellites)
- This is long-continued and well successful project ldquoIntelsatrdquo (the Intelsat II series of satellites first launched in 1966) including 8th generation of geostationary communications satellites and Intelsat VI (1991) designed and built by Hughes Aircraft Company - The ldquoMeteosatrdquo-project by European Space Research Organization (initiated with Meteosat-1 in 1977 and operated until 2007 with
Meteosat-7) also used dual-spin configuration spacecraft - Spin-stabilized spacecraft with mechanically despun antennas was applied in the framework of GEOTAIL (a collaborative mission
of Japan JAXAISAS and NASA within the program ldquoInternational Solar-Terrestrial Physicsrdquo) launched in 1992 the GEOTAIL spacecraft and its payload continue to operate in 2013
- Analogously the construction scheme with despun antenna was selected for Chinese communications satellites DFH-2 (STW-3 1988 STW-4 1988 STW-55 1990)
- Well-known Galileo missionrsquos spacecraft (the fifth spacecraft to visit Jupiter launched on October 19 1989) was designed by dual-spin scheme
- Of course we need to indicate one of the worlds most-purchased commercial communications satellite models such as Hughes Boeing HS-376 BSS-376 (for example Satellite Business Systems with projects SBS 1 2 3 4 5 6 HGS 5 etc) they have spun section containing propulsion system solar drums and despun section containing the satellites communications payload and antennas
- Also very popular and versatile dual-spin models are Hughes HS-381 (Leasat project) HS-389 (Intelsat project) HS-393 (JCSat project)
The DSSC usually is used for the attitude stabilization by partial twist method only one of the DSSCs coaxial bodies (the laquorotorraquo-body) has rotation at the laquoquiescenceraquo of the second body (the laquoplatformraquo-body) ndash it allows to place into the laquoplatformraquo-body some exploratory equipment and to perform of space-mission tests without rotational disturbances
Spin StabilizationDual-Spin Spacecraft
4
HS 376Class Communications Nation USA
Mass 654 kg at beginning-of-life in geosynchronous orbit
Spin stabilized at 50 rpm by 4 hydrazine thrusters with 136 kg propellant Star 30 apogee kick motor Solar cells mounted on outside of cylindrical satellite body provide 990 W of power and recharge two NiCd batteries 24 + 6 backup 9 W transmission beams
HS 376 Chronology- 15 November 1980 SBS 1 Program- hellip- 22 November 1998 BONUM-1 Program
Spin StabilizationDual-Spin Spacecraft
4
Hughes HS-389
Intelsat-6 [Boeing] SDS-2 [NRO]
Ordered Date
Intelsat 601 1982 29101991
Intelsat 602 1982 27101989
Intelsat 603 1982 14031990
Intelsat 604 1982 23061990
Intelsat 605 1982 14081991
SDS-2 1 08081989
SDS-2 2 15111990
SDS-2 3 02121992
SDS-2 4 03071996
Gravity Gradient Stabilization 5
UniCubeSat-GG is the first CubeSat mission of GAUSS (Gruppo di Astrodinamica dell Universita degli Studi ldquola Sapienzardquo) at the University of Rome (Universita di Roma ldquoLa Sapienzardquo Scuola di Ingegneria Aerospaziale) Italy
The Gravity-gradient stabilization is a method of SC stabilizing in a fixed orientation using only the orbited bodys mass distribution and the Earths gravitational field
SC is placed along the radius-vector of the Earth
Tether-satellitesPhysical pendulums
Magnetic Stabilization 6
Magnetic stabilization is a method of SC stabilizing using geomagnetic field of the Earth
SC is positioned along the magnetic lines of the geomagnetic field (ldquomagnetic compassrdquo)
One of Four Alinco-5 Permanent Magnet sets on board KySat-1
KySat-1 Passive Magnetic Stabilization System is used for antenna orientation and coarse camera pointing
KySat-1 the first satellite project by Kentucky Space is a 1-U CubeSat scheduled to launch in 2010 on a NASA mission
Aerodynamic Stabilization 7
The Aerodynamic stabilization is a method of SC stabilizing using aerodynamic force in rarefied atmosphere of low earth orbit
SC is positioned along the orbital velocity vector
Aerodynamically Stable CubeSat Design Concept
ldquogo like an arrow helliprdquo
SC with tail unit
Actuators 8Reaction Wheel Assemblies (RWAs)
RWAs are particularly useful when the spacecraft must be rotated by very small amounts such as keeping a telescope pointed at a star
This is accomplished by equipping the spacecraft with an electric motor attached to a flywheel which when rotated increasingly fast causes the spacecraft to spin the other way in a proportional amount by conservation of angular momentum
Actuators 9Control Moment Gyros (CMGs)
A CMG consists of a spinning rotor and one or more motorized gimbals that tilt the rotorrsquos angular momentum As the rotor tilts the changing angular momentum causes a gyroscopic torque that rotates the spacecraft
Microsatellite with four control moment gyroscopes
Actuators 10Thrusters
A thruster is a small propulsive device used by spacecraft for attitude control in the reaction control system or long-duration low-thrust acceleration
Liquefied gases in high-pressure balloons
Main Equations of Angular Motion of Rigid Body(Attitude Motion of SC)
11
Euler dynamical equations
Euler kinematical equations
The study of the angular motion of the SC attitude dynamics is one of the main problems of rigid body systems dynamics in the classical mechanics
And vice versa
Tasks of analysis and synthesis of the rigid bodiesrsquo motion have important applications in the space-flight dynamics
Main Properties of the Free Angular Motion of Rigid Body(Attitude Motion of SC)
12
Louis Poinsot interpreacutetation
Inertia tensor with polhodes
--- notation by CDHall
Main Properties of the Free Angular Motion of Rigid Body(Attitude Motion of SC)
12
If we consider rigid body angular motion on the base of Hamilton dynamics than for rigid body motion we take pendulum phase structure
x=tetta (nutation) and
y = impulse (tetta) ~ d(tetta)dt
Pendulum phase space
Part 2 ndash Research Results
1 The magnetized dual-spin spacecraft attitude motion
2 The regular and chaotic dynamics of dual-spin spacecraft
3 The multi-rotor system and multi-spin spacecraft dynamics
13
14
Letrsquos consider an angular motion (about point O) of spider-type multiple rotor rigid bodies systems and
coaxial bodies systems
Mechanical models of multiple-rotor systems
Coaxial bodies system(dual-spin spacecraft)
Multirotor spiders(gyrostat-spacecrafts)
Number of rotors = N
Number of rotors = 6 Number of rotors = 1
1cos sin
cos
sin cos
sincos sin
cos
p q
p q
r p q
(1)
(2)
15
I1 The angular motion general equations
I The coaxial bodies system motion
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
cos sinP
P Q M Q
The coaxial top
I2 The angular motion equations of the magnetic DSSC and the coaxial Lagrange top
16
The single dipole model of the Earthrsquos magnetic field and the constant magnetic field vector corresponding to the circle equatorial orbit
The magnetic DSSC coordinate frames
17I3 The equations
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
2 2 2
2 1
0
T
x y zOx y z
T
orb orb
M M M
B m B m
oθ
θ
rbM m B
M
1 2
2 2
3 2
cos
cos
cos
OZ Ox
OZ Oy
OZ Oz
i k
j k
k k
2 2
2 1
2
0
Ap C B qr q Q
Bq A C pr p Q
C r B A pq M
orbQ B m
1
22 2 2 2 22
1 2 1 2 1 2
sin cos 1
2 2
T P
LI L l lT
A A A B C C
H H
cos sinP
P Q M Q
(6)
(5)
(4)
(3)
(2)
(1)
18I4 The integrals and solutions
2
2
2
1
2
23
x
y
z
K Ap
K KK Bq
K KK C r
K K
2
2
2
2 3
2
const
cos
z
z
L K C r
I I K
K C rL
K K K
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
2
2 2 22 2
1
2 2Ap Bq C r E C r TC
22 2 2 2 22 2A p B q C r K DT
2 1 2
22 21
2
22 2
Bq A C f q f q
C B C Ff q V E
A A B A A B
H B A B qf q V V
C A C
- AV Doroshin Exact Solutions in Attitude Dynamics of a Magnetic Dual-Spin Spacecraft and a Generalization of the Lagrange Top WSEAS Transactions on Systems Issue 10 Volume 12 (2013)
471-482
(11) (10)
(9)
(8) (7)
19I5 The analytical solution
The polhodes ellipsoid
2
2 2
22 2
2 1
1
1
q t H C A C x t SB A B
p t C B C x t FA A B
EAr t x t S t r t
A C C
2 20 0
2 20 0
sn
sn
i
i
R P c N t t I kx t e
R P c N t t I k
S E
The numerical integration (lines) and analytical (points) results
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075 q0=2 r0=583 [1s] K=50
[kgm2s] Q=100 [kgm2s2]
5
(13)
(12)
20I6 The analytical solution for Euler angles
orbB
K2K + ω timesK = mtimesK
K + ΩtimesK = 0
orbB
K 2Ω ω m
γ + Ωtimes γ = 0
1
2
3 2
t Ap t K
t Bq t K
C r t K
2cos
tg
t C r t K
Ap tt
Bq t
0
0
2 2
0 2 2 2 2
01
( ) ( )
( ) ( )
( )
t
t
t
t
Ap t Bq tt K dt
A p t B q t
t r t dtC
5
10 20 3003 052 08
The numerical integration (lines) and analytical (points) results for the directional cosines
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075
q0=2 r0=583 [1s] K=50 [km2s]
Q=100 [kgm2s2]
(19)
(20)
(18) (17)
(16)
(15)
(14)
21I7 Hamilton form of equations in the Andoyer-Deprit variables
(21)
(25)
(22)
(23)
(24)
1 C r
22
3 23
T T
T
L I Kl
I L I
K k K s K
K k
2
2
2
2 22
2 22
2
sin
cos
x
y
z
K Ap I L l
K Bq I L l
K C r L
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
22 2 2 2 22
1 2 1 2 1 2 2
sin cos 1
2 2
LI L l l LQ
A A A B C C I
H
22
(26)
Hamilton form of equations 2 2 2 1 1A B C A C
Equations (21) have heteroclinic solutions
Perturbations
0 0 L lM t f l t L t g t t dt
Melnikov function
(28)
The Melnikov function has the infinite number of simple roots This proves the fact of the motion chaotization at the presence of small harmonic perturbations
22 2 2 2
2 1
C B C EB
p t y t q t s k y t E r t y t t r tA A B B C C
0
sin cosN
n p n pn
Q t a n t b n t
22 2 2 2 2
20 0
1 2 1 2 1 2 2 20 1 0 1
sin cos 1
2 2
LI L l l L LQ Q Q t
A A A B C C I I
H H H H H
0 0 1 1
L L
L l L l
l l
L f l L gf f g g
l L l Ll f l L g
H H H H
0 0 00
cos sinN
ns n p n p
n
M t J a n t b n t
(27)
(26)
00 0 2
2
00 1 2 02
4 exp
exp 4
M aa E y t
ky t
Mt aE y a a a
k
23
2 l L I
I8 Numerical modeling Poincareacute sections mod 2 0pt
2 22 2 2 1 1 2 1 3 5
0 0 0 0
15 10 6 5 4[ ] 20 5 [ ] 075 [1 ] 1 5 20 [1]
) 5 004 ) 5 01 ) 10 01 ) 15 02
pA B C A C kg m I kg m s s a a a
a Q b Q c Q d Q
(a) (b)
(c) (d)
II The spider-type systems motion 24
m r K K K
1 2
3 4
5 6
4 2 m r
Ap p
Bq J I q I
Cr r
K K
ed
dt
Kω K M
12 56 34
34 12 56
56 34 12
ex
ey
ez
Ap I C B qr I q r M
Bq I A C pr I r p M
Cr I B A pq I p q M
4 2
4 2 4 2
iji j A A J I
B B J I C C J I
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i ex x
i e i ey y
i e i ez z
I p M M I p M M
I q M M I q M M
I r M M I r M M
(1)
(2)
(3)
(4)
II1 Angular momentum of the system in projections onto axes of the frame Oxyz
II2 The motion equations of the multirotor system
25
1 1
1 1
4 2
4 2 4 2
N Nij
il jl ll l
N N
l ll l
A A J NI
B B J NI C C J NI
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i el l lx l l lx
i e i el l ly l l ly
i e i el l lz l l lz
I p M M I p M M
I q M M I q M M
I r M M I r M M
0
1
2
3
cos 2
cos sin2
cos sin2
cos sin2
2 λ Θ λ
0
1
2
3
0
0
0
0
p q r
p r q
q r p
r q p
λ Θ
(4rsquo)
II3 The Euler parameters
(5)
26II4 The conjugate spinups and captures
Def1 Conjugate rotors are paired rotors located in the same layer on the opposite rays For example rotor 3N and rotor 4N are conjugate rotors (also rotor 12 and rotor 22 etc)
Def2 Conjugate spinup mean a process of spinning up conjugate rotors in opposite directions up to a desired value of relative angular velocity with the help of internal moments from main body Velocities of conjugate rotors will be equal in absolute value and opposite in sign
Def3 Rotor capture is an immediate deceleration of rotor relative angular velocity with the help of internal moment from the main body So rotor capture means an ldquoinstantaneous freezingrdquo of rotor with respect to the main body The capture can be performed with the help of gear meshing friction clutch or other methods
27
(6)
II6 Analytical solutions of motion equations
0e e ex y zM M M
A B C D
12 121
12 122
0
0
0
0
si
si
M if t tM
otherwise
M if t tM
otherwise
12 12 12sS M t I
1 12 2 12S S
1 1 12c c st t t
1 0
12
122
ISp
A IAS
A I
1 0 Conjugate spinup of rotors 1 2
Rotor 1 capture
Rotor 2 capture
2 2 1c c ct t t
1 2
121 2
0 0
c c
c c
t t tp IS
P t t tA I
Two serial captures of conjugate rotors bring to piecewise constant angular velocity of the main body
The main body performed the rotation about Ox axis by finite angle 12 2 1
c c
x
IS t t
A I
28
1 3 5 2 4 6
0 1 2 3
1 0
c c c c c c c cstart finish
c c c cstart start start start
t t t t t t t t
t t t t
0 1
2 3
2 2 2
cos sin2 2
sin sin2 2
c cstart start
c cstart start
c c c cstart finish finish start
t t t tPt t
t t t tQ Rt t
P Q R t t t T t t
1 2 t t t p P q Q r R
Letrsquos assume synchronically captures of coresponded conjugate rotors 1 2 3 4 5 6 and coincidence of the frame Oxyz initial position and the fixed frame OXYZ
Angular velocities between conjugate captures of rotors
Solutions of kinematic equations (5)
cos cos cosT
P Q R
T
e
The main body performed finite rotation about vector e by angle χ
(18)
(20)
(19)
(21)
29II7 Numerical simulation of reorientation process
const 0 1 135 246
i s cj jj j j
i s cj jj j j
jj
M M H t H t t H t t
M M H t H t t H t t
M j j
Two sets of results of numerical simulation
1 4 5(0) (0) (0) 0 (0) 100 1 s ω
ν = 300 Nms
H(t) is Heaviside function
FigA - zero value of angular momentum and different inertia moments of main body
Fig A Fig B
Fig4 - reorientation process at nonzero system angular momentum
30
__________________________________________________________
The main properties of the attitude stabilization and control of SC (and multirotor systems) have been examined
Research into attitude motion of the one-body-SC dual-spin SC and spider-type-SC is very complicated
Nontrivial and chaotic modes are possible in the SC attitude motion
Conclusion
- Slide 1
- Outline
- Part 1 - Introduction to Attitude Dynamics and Control
- Slide 4
- Spin stabilization
- Spin Stabilization Dual-Spin Spacecraft
- Spin Stabilization Dual-Spin Spacecraft (2)
- Spin Stabilization Dual-Spin Spacecraft (3)
- Spin Stabilization Dual-Spin Spacecraft (4)
- Gravity Gradient Stabilization
- Magnetic Stabilization
- Aerodynamic Stabilization
- Actuators
- Actuators (2)
- Actuators (3)
- Main Equations of Angular Motion of Rigid Body (Attitude Motion
- Main Properties of the Free Angular Motion of Rigid Body (Attit
- Main Properties of the Free Angular Motion of Rigid Body (Attit (2)
- Part 2 ndash Research Results
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
-
Spin StabilizationDual-Spin Spacecraft
4
TACSAT I was the largest and most powerful communications satellite at the time when it was launched into synchronous orbit by a Titan IIIC booster 9 February 1969 from Cape Canaveral Florida
TACSAT I The antenna is the platform and is intended to point continuously at the Earth spinning at one evolution per orbit The cylindrical body is the rotor providing gyroscopic stability through its 60 RPM spin
Spin StabilizationDual-Spin Spacecraft
4
The dual-spin construction-scheme is quite useful in the practice during all history of space flights realization and it is possible to present some examples of the DSSC which was used in real space-programs (most of them are communications satellites and observing geostationary satellites)
- This is long-continued and well successful project ldquoIntelsatrdquo (the Intelsat II series of satellites first launched in 1966) including 8th generation of geostationary communications satellites and Intelsat VI (1991) designed and built by Hughes Aircraft Company - The ldquoMeteosatrdquo-project by European Space Research Organization (initiated with Meteosat-1 in 1977 and operated until 2007 with
Meteosat-7) also used dual-spin configuration spacecraft - Spin-stabilized spacecraft with mechanically despun antennas was applied in the framework of GEOTAIL (a collaborative mission
of Japan JAXAISAS and NASA within the program ldquoInternational Solar-Terrestrial Physicsrdquo) launched in 1992 the GEOTAIL spacecraft and its payload continue to operate in 2013
- Analogously the construction scheme with despun antenna was selected for Chinese communications satellites DFH-2 (STW-3 1988 STW-4 1988 STW-55 1990)
- Well-known Galileo missionrsquos spacecraft (the fifth spacecraft to visit Jupiter launched on October 19 1989) was designed by dual-spin scheme
- Of course we need to indicate one of the worlds most-purchased commercial communications satellite models such as Hughes Boeing HS-376 BSS-376 (for example Satellite Business Systems with projects SBS 1 2 3 4 5 6 HGS 5 etc) they have spun section containing propulsion system solar drums and despun section containing the satellites communications payload and antennas
- Also very popular and versatile dual-spin models are Hughes HS-381 (Leasat project) HS-389 (Intelsat project) HS-393 (JCSat project)
The DSSC usually is used for the attitude stabilization by partial twist method only one of the DSSCs coaxial bodies (the laquorotorraquo-body) has rotation at the laquoquiescenceraquo of the second body (the laquoplatformraquo-body) ndash it allows to place into the laquoplatformraquo-body some exploratory equipment and to perform of space-mission tests without rotational disturbances
Spin StabilizationDual-Spin Spacecraft
4
HS 376Class Communications Nation USA
Mass 654 kg at beginning-of-life in geosynchronous orbit
Spin stabilized at 50 rpm by 4 hydrazine thrusters with 136 kg propellant Star 30 apogee kick motor Solar cells mounted on outside of cylindrical satellite body provide 990 W of power and recharge two NiCd batteries 24 + 6 backup 9 W transmission beams
HS 376 Chronology- 15 November 1980 SBS 1 Program- hellip- 22 November 1998 BONUM-1 Program
Spin StabilizationDual-Spin Spacecraft
4
Hughes HS-389
Intelsat-6 [Boeing] SDS-2 [NRO]
Ordered Date
Intelsat 601 1982 29101991
Intelsat 602 1982 27101989
Intelsat 603 1982 14031990
Intelsat 604 1982 23061990
Intelsat 605 1982 14081991
SDS-2 1 08081989
SDS-2 2 15111990
SDS-2 3 02121992
SDS-2 4 03071996
Gravity Gradient Stabilization 5
UniCubeSat-GG is the first CubeSat mission of GAUSS (Gruppo di Astrodinamica dell Universita degli Studi ldquola Sapienzardquo) at the University of Rome (Universita di Roma ldquoLa Sapienzardquo Scuola di Ingegneria Aerospaziale) Italy
The Gravity-gradient stabilization is a method of SC stabilizing in a fixed orientation using only the orbited bodys mass distribution and the Earths gravitational field
SC is placed along the radius-vector of the Earth
Tether-satellitesPhysical pendulums
Magnetic Stabilization 6
Magnetic stabilization is a method of SC stabilizing using geomagnetic field of the Earth
SC is positioned along the magnetic lines of the geomagnetic field (ldquomagnetic compassrdquo)
One of Four Alinco-5 Permanent Magnet sets on board KySat-1
KySat-1 Passive Magnetic Stabilization System is used for antenna orientation and coarse camera pointing
KySat-1 the first satellite project by Kentucky Space is a 1-U CubeSat scheduled to launch in 2010 on a NASA mission
Aerodynamic Stabilization 7
The Aerodynamic stabilization is a method of SC stabilizing using aerodynamic force in rarefied atmosphere of low earth orbit
SC is positioned along the orbital velocity vector
Aerodynamically Stable CubeSat Design Concept
ldquogo like an arrow helliprdquo
SC with tail unit
Actuators 8Reaction Wheel Assemblies (RWAs)
RWAs are particularly useful when the spacecraft must be rotated by very small amounts such as keeping a telescope pointed at a star
This is accomplished by equipping the spacecraft with an electric motor attached to a flywheel which when rotated increasingly fast causes the spacecraft to spin the other way in a proportional amount by conservation of angular momentum
Actuators 9Control Moment Gyros (CMGs)
A CMG consists of a spinning rotor and one or more motorized gimbals that tilt the rotorrsquos angular momentum As the rotor tilts the changing angular momentum causes a gyroscopic torque that rotates the spacecraft
Microsatellite with four control moment gyroscopes
Actuators 10Thrusters
A thruster is a small propulsive device used by spacecraft for attitude control in the reaction control system or long-duration low-thrust acceleration
Liquefied gases in high-pressure balloons
Main Equations of Angular Motion of Rigid Body(Attitude Motion of SC)
11
Euler dynamical equations
Euler kinematical equations
The study of the angular motion of the SC attitude dynamics is one of the main problems of rigid body systems dynamics in the classical mechanics
And vice versa
Tasks of analysis and synthesis of the rigid bodiesrsquo motion have important applications in the space-flight dynamics
Main Properties of the Free Angular Motion of Rigid Body(Attitude Motion of SC)
12
Louis Poinsot interpreacutetation
Inertia tensor with polhodes
--- notation by CDHall
Main Properties of the Free Angular Motion of Rigid Body(Attitude Motion of SC)
12
If we consider rigid body angular motion on the base of Hamilton dynamics than for rigid body motion we take pendulum phase structure
x=tetta (nutation) and
y = impulse (tetta) ~ d(tetta)dt
Pendulum phase space
Part 2 ndash Research Results
1 The magnetized dual-spin spacecraft attitude motion
2 The regular and chaotic dynamics of dual-spin spacecraft
3 The multi-rotor system and multi-spin spacecraft dynamics
13
14
Letrsquos consider an angular motion (about point O) of spider-type multiple rotor rigid bodies systems and
coaxial bodies systems
Mechanical models of multiple-rotor systems
Coaxial bodies system(dual-spin spacecraft)
Multirotor spiders(gyrostat-spacecrafts)
Number of rotors = N
Number of rotors = 6 Number of rotors = 1
1cos sin
cos
sin cos
sincos sin
cos
p q
p q
r p q
(1)
(2)
15
I1 The angular motion general equations
I The coaxial bodies system motion
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
cos sinP
P Q M Q
The coaxial top
I2 The angular motion equations of the magnetic DSSC and the coaxial Lagrange top
16
The single dipole model of the Earthrsquos magnetic field and the constant magnetic field vector corresponding to the circle equatorial orbit
The magnetic DSSC coordinate frames
17I3 The equations
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
2 2 2
2 1
0
T
x y zOx y z
T
orb orb
M M M
B m B m
oθ
θ
rbM m B
M
1 2
2 2
3 2
cos
cos
cos
OZ Ox
OZ Oy
OZ Oz
i k
j k
k k
2 2
2 1
2
0
Ap C B qr q Q
Bq A C pr p Q
C r B A pq M
orbQ B m
1
22 2 2 2 22
1 2 1 2 1 2
sin cos 1
2 2
T P
LI L l lT
A A A B C C
H H
cos sinP
P Q M Q
(6)
(5)
(4)
(3)
(2)
(1)
18I4 The integrals and solutions
2
2
2
1
2
23
x
y
z
K Ap
K KK Bq
K KK C r
K K
2
2
2
2 3
2
const
cos
z
z
L K C r
I I K
K C rL
K K K
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
2
2 2 22 2
1
2 2Ap Bq C r E C r TC
22 2 2 2 22 2A p B q C r K DT
2 1 2
22 21
2
22 2
Bq A C f q f q
C B C Ff q V E
A A B A A B
H B A B qf q V V
C A C
- AV Doroshin Exact Solutions in Attitude Dynamics of a Magnetic Dual-Spin Spacecraft and a Generalization of the Lagrange Top WSEAS Transactions on Systems Issue 10 Volume 12 (2013)
471-482
(11) (10)
(9)
(8) (7)
19I5 The analytical solution
The polhodes ellipsoid
2
2 2
22 2
2 1
1
1
q t H C A C x t SB A B
p t C B C x t FA A B
EAr t x t S t r t
A C C
2 20 0
2 20 0
sn
sn
i
i
R P c N t t I kx t e
R P c N t t I k
S E
The numerical integration (lines) and analytical (points) results
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075 q0=2 r0=583 [1s] K=50
[kgm2s] Q=100 [kgm2s2]
5
(13)
(12)
20I6 The analytical solution for Euler angles
orbB
K2K + ω timesK = mtimesK
K + ΩtimesK = 0
orbB
K 2Ω ω m
γ + Ωtimes γ = 0
1
2
3 2
t Ap t K
t Bq t K
C r t K
2cos
tg
t C r t K
Ap tt
Bq t
0
0
2 2
0 2 2 2 2
01
( ) ( )
( ) ( )
( )
t
t
t
t
Ap t Bq tt K dt
A p t B q t
t r t dtC
5
10 20 3003 052 08
The numerical integration (lines) and analytical (points) results for the directional cosines
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075
q0=2 r0=583 [1s] K=50 [km2s]
Q=100 [kgm2s2]
(19)
(20)
(18) (17)
(16)
(15)
(14)
21I7 Hamilton form of equations in the Andoyer-Deprit variables
(21)
(25)
(22)
(23)
(24)
1 C r
22
3 23
T T
T
L I Kl
I L I
K k K s K
K k
2
2
2
2 22
2 22
2
sin
cos
x
y
z
K Ap I L l
K Bq I L l
K C r L
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
22 2 2 2 22
1 2 1 2 1 2 2
sin cos 1
2 2
LI L l l LQ
A A A B C C I
H
22
(26)
Hamilton form of equations 2 2 2 1 1A B C A C
Equations (21) have heteroclinic solutions
Perturbations
0 0 L lM t f l t L t g t t dt
Melnikov function
(28)
The Melnikov function has the infinite number of simple roots This proves the fact of the motion chaotization at the presence of small harmonic perturbations
22 2 2 2
2 1
C B C EB
p t y t q t s k y t E r t y t t r tA A B B C C
0
sin cosN
n p n pn
Q t a n t b n t
22 2 2 2 2
20 0
1 2 1 2 1 2 2 20 1 0 1
sin cos 1
2 2
LI L l l L LQ Q Q t
A A A B C C I I
H H H H H
0 0 1 1
L L
L l L l
l l
L f l L gf f g g
l L l Ll f l L g
H H H H
0 0 00
cos sinN
ns n p n p
n
M t J a n t b n t
(27)
(26)
00 0 2
2
00 1 2 02
4 exp
exp 4
M aa E y t
ky t
Mt aE y a a a
k
23
2 l L I
I8 Numerical modeling Poincareacute sections mod 2 0pt
2 22 2 2 1 1 2 1 3 5
0 0 0 0
15 10 6 5 4[ ] 20 5 [ ] 075 [1 ] 1 5 20 [1]
) 5 004 ) 5 01 ) 10 01 ) 15 02
pA B C A C kg m I kg m s s a a a
a Q b Q c Q d Q
(a) (b)
(c) (d)
II The spider-type systems motion 24
m r K K K
1 2
3 4
5 6
4 2 m r
Ap p
Bq J I q I
Cr r
K K
ed
dt
Kω K M
12 56 34
34 12 56
56 34 12
ex
ey
ez
Ap I C B qr I q r M
Bq I A C pr I r p M
Cr I B A pq I p q M
4 2
4 2 4 2
iji j A A J I
B B J I C C J I
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i ex x
i e i ey y
i e i ez z
I p M M I p M M
I q M M I q M M
I r M M I r M M
(1)
(2)
(3)
(4)
II1 Angular momentum of the system in projections onto axes of the frame Oxyz
II2 The motion equations of the multirotor system
25
1 1
1 1
4 2
4 2 4 2
N Nij
il jl ll l
N N
l ll l
A A J NI
B B J NI C C J NI
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i el l lx l l lx
i e i el l ly l l ly
i e i el l lz l l lz
I p M M I p M M
I q M M I q M M
I r M M I r M M
0
1
2
3
cos 2
cos sin2
cos sin2
cos sin2
2 λ Θ λ
0
1
2
3
0
0
0
0
p q r
p r q
q r p
r q p
λ Θ
(4rsquo)
II3 The Euler parameters
(5)
26II4 The conjugate spinups and captures
Def1 Conjugate rotors are paired rotors located in the same layer on the opposite rays For example rotor 3N and rotor 4N are conjugate rotors (also rotor 12 and rotor 22 etc)
Def2 Conjugate spinup mean a process of spinning up conjugate rotors in opposite directions up to a desired value of relative angular velocity with the help of internal moments from main body Velocities of conjugate rotors will be equal in absolute value and opposite in sign
Def3 Rotor capture is an immediate deceleration of rotor relative angular velocity with the help of internal moment from the main body So rotor capture means an ldquoinstantaneous freezingrdquo of rotor with respect to the main body The capture can be performed with the help of gear meshing friction clutch or other methods
27
(6)
II6 Analytical solutions of motion equations
0e e ex y zM M M
A B C D
12 121
12 122
0
0
0
0
si
si
M if t tM
otherwise
M if t tM
otherwise
12 12 12sS M t I
1 12 2 12S S
1 1 12c c st t t
1 0
12
122
ISp
A IAS
A I
1 0 Conjugate spinup of rotors 1 2
Rotor 1 capture
Rotor 2 capture
2 2 1c c ct t t
1 2
121 2
0 0
c c
c c
t t tp IS
P t t tA I
Two serial captures of conjugate rotors bring to piecewise constant angular velocity of the main body
The main body performed the rotation about Ox axis by finite angle 12 2 1
c c
x
IS t t
A I
28
1 3 5 2 4 6
0 1 2 3
1 0
c c c c c c c cstart finish
c c c cstart start start start
t t t t t t t t
t t t t
0 1
2 3
2 2 2
cos sin2 2
sin sin2 2
c cstart start
c cstart start
c c c cstart finish finish start
t t t tPt t
t t t tQ Rt t
P Q R t t t T t t
1 2 t t t p P q Q r R
Letrsquos assume synchronically captures of coresponded conjugate rotors 1 2 3 4 5 6 and coincidence of the frame Oxyz initial position and the fixed frame OXYZ
Angular velocities between conjugate captures of rotors
Solutions of kinematic equations (5)
cos cos cosT
P Q R
T
e
The main body performed finite rotation about vector e by angle χ
(18)
(20)
(19)
(21)
29II7 Numerical simulation of reorientation process
const 0 1 135 246
i s cj jj j j
i s cj jj j j
jj
M M H t H t t H t t
M M H t H t t H t t
M j j
Two sets of results of numerical simulation
1 4 5(0) (0) (0) 0 (0) 100 1 s ω
ν = 300 Nms
H(t) is Heaviside function
FigA - zero value of angular momentum and different inertia moments of main body
Fig A Fig B
Fig4 - reorientation process at nonzero system angular momentum
30
__________________________________________________________
The main properties of the attitude stabilization and control of SC (and multirotor systems) have been examined
Research into attitude motion of the one-body-SC dual-spin SC and spider-type-SC is very complicated
Nontrivial and chaotic modes are possible in the SC attitude motion
Conclusion
- Slide 1
- Outline
- Part 1 - Introduction to Attitude Dynamics and Control
- Slide 4
- Spin stabilization
- Spin Stabilization Dual-Spin Spacecraft
- Spin Stabilization Dual-Spin Spacecraft (2)
- Spin Stabilization Dual-Spin Spacecraft (3)
- Spin Stabilization Dual-Spin Spacecraft (4)
- Gravity Gradient Stabilization
- Magnetic Stabilization
- Aerodynamic Stabilization
- Actuators
- Actuators (2)
- Actuators (3)
- Main Equations of Angular Motion of Rigid Body (Attitude Motion
- Main Properties of the Free Angular Motion of Rigid Body (Attit
- Main Properties of the Free Angular Motion of Rigid Body (Attit (2)
- Part 2 ndash Research Results
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
-
Spin StabilizationDual-Spin Spacecraft
4
The dual-spin construction-scheme is quite useful in the practice during all history of space flights realization and it is possible to present some examples of the DSSC which was used in real space-programs (most of them are communications satellites and observing geostationary satellites)
- This is long-continued and well successful project ldquoIntelsatrdquo (the Intelsat II series of satellites first launched in 1966) including 8th generation of geostationary communications satellites and Intelsat VI (1991) designed and built by Hughes Aircraft Company - The ldquoMeteosatrdquo-project by European Space Research Organization (initiated with Meteosat-1 in 1977 and operated until 2007 with
Meteosat-7) also used dual-spin configuration spacecraft - Spin-stabilized spacecraft with mechanically despun antennas was applied in the framework of GEOTAIL (a collaborative mission
of Japan JAXAISAS and NASA within the program ldquoInternational Solar-Terrestrial Physicsrdquo) launched in 1992 the GEOTAIL spacecraft and its payload continue to operate in 2013
- Analogously the construction scheme with despun antenna was selected for Chinese communications satellites DFH-2 (STW-3 1988 STW-4 1988 STW-55 1990)
- Well-known Galileo missionrsquos spacecraft (the fifth spacecraft to visit Jupiter launched on October 19 1989) was designed by dual-spin scheme
- Of course we need to indicate one of the worlds most-purchased commercial communications satellite models such as Hughes Boeing HS-376 BSS-376 (for example Satellite Business Systems with projects SBS 1 2 3 4 5 6 HGS 5 etc) they have spun section containing propulsion system solar drums and despun section containing the satellites communications payload and antennas
- Also very popular and versatile dual-spin models are Hughes HS-381 (Leasat project) HS-389 (Intelsat project) HS-393 (JCSat project)
The DSSC usually is used for the attitude stabilization by partial twist method only one of the DSSCs coaxial bodies (the laquorotorraquo-body) has rotation at the laquoquiescenceraquo of the second body (the laquoplatformraquo-body) ndash it allows to place into the laquoplatformraquo-body some exploratory equipment and to perform of space-mission tests without rotational disturbances
Spin StabilizationDual-Spin Spacecraft
4
HS 376Class Communications Nation USA
Mass 654 kg at beginning-of-life in geosynchronous orbit
Spin stabilized at 50 rpm by 4 hydrazine thrusters with 136 kg propellant Star 30 apogee kick motor Solar cells mounted on outside of cylindrical satellite body provide 990 W of power and recharge two NiCd batteries 24 + 6 backup 9 W transmission beams
HS 376 Chronology- 15 November 1980 SBS 1 Program- hellip- 22 November 1998 BONUM-1 Program
Spin StabilizationDual-Spin Spacecraft
4
Hughes HS-389
Intelsat-6 [Boeing] SDS-2 [NRO]
Ordered Date
Intelsat 601 1982 29101991
Intelsat 602 1982 27101989
Intelsat 603 1982 14031990
Intelsat 604 1982 23061990
Intelsat 605 1982 14081991
SDS-2 1 08081989
SDS-2 2 15111990
SDS-2 3 02121992
SDS-2 4 03071996
Gravity Gradient Stabilization 5
UniCubeSat-GG is the first CubeSat mission of GAUSS (Gruppo di Astrodinamica dell Universita degli Studi ldquola Sapienzardquo) at the University of Rome (Universita di Roma ldquoLa Sapienzardquo Scuola di Ingegneria Aerospaziale) Italy
The Gravity-gradient stabilization is a method of SC stabilizing in a fixed orientation using only the orbited bodys mass distribution and the Earths gravitational field
SC is placed along the radius-vector of the Earth
Tether-satellitesPhysical pendulums
Magnetic Stabilization 6
Magnetic stabilization is a method of SC stabilizing using geomagnetic field of the Earth
SC is positioned along the magnetic lines of the geomagnetic field (ldquomagnetic compassrdquo)
One of Four Alinco-5 Permanent Magnet sets on board KySat-1
KySat-1 Passive Magnetic Stabilization System is used for antenna orientation and coarse camera pointing
KySat-1 the first satellite project by Kentucky Space is a 1-U CubeSat scheduled to launch in 2010 on a NASA mission
Aerodynamic Stabilization 7
The Aerodynamic stabilization is a method of SC stabilizing using aerodynamic force in rarefied atmosphere of low earth orbit
SC is positioned along the orbital velocity vector
Aerodynamically Stable CubeSat Design Concept
ldquogo like an arrow helliprdquo
SC with tail unit
Actuators 8Reaction Wheel Assemblies (RWAs)
RWAs are particularly useful when the spacecraft must be rotated by very small amounts such as keeping a telescope pointed at a star
This is accomplished by equipping the spacecraft with an electric motor attached to a flywheel which when rotated increasingly fast causes the spacecraft to spin the other way in a proportional amount by conservation of angular momentum
Actuators 9Control Moment Gyros (CMGs)
A CMG consists of a spinning rotor and one or more motorized gimbals that tilt the rotorrsquos angular momentum As the rotor tilts the changing angular momentum causes a gyroscopic torque that rotates the spacecraft
Microsatellite with four control moment gyroscopes
Actuators 10Thrusters
A thruster is a small propulsive device used by spacecraft for attitude control in the reaction control system or long-duration low-thrust acceleration
Liquefied gases in high-pressure balloons
Main Equations of Angular Motion of Rigid Body(Attitude Motion of SC)
11
Euler dynamical equations
Euler kinematical equations
The study of the angular motion of the SC attitude dynamics is one of the main problems of rigid body systems dynamics in the classical mechanics
And vice versa
Tasks of analysis and synthesis of the rigid bodiesrsquo motion have important applications in the space-flight dynamics
Main Properties of the Free Angular Motion of Rigid Body(Attitude Motion of SC)
12
Louis Poinsot interpreacutetation
Inertia tensor with polhodes
--- notation by CDHall
Main Properties of the Free Angular Motion of Rigid Body(Attitude Motion of SC)
12
If we consider rigid body angular motion on the base of Hamilton dynamics than for rigid body motion we take pendulum phase structure
x=tetta (nutation) and
y = impulse (tetta) ~ d(tetta)dt
Pendulum phase space
Part 2 ndash Research Results
1 The magnetized dual-spin spacecraft attitude motion
2 The regular and chaotic dynamics of dual-spin spacecraft
3 The multi-rotor system and multi-spin spacecraft dynamics
13
14
Letrsquos consider an angular motion (about point O) of spider-type multiple rotor rigid bodies systems and
coaxial bodies systems
Mechanical models of multiple-rotor systems
Coaxial bodies system(dual-spin spacecraft)
Multirotor spiders(gyrostat-spacecrafts)
Number of rotors = N
Number of rotors = 6 Number of rotors = 1
1cos sin
cos
sin cos
sincos sin
cos
p q
p q
r p q
(1)
(2)
15
I1 The angular motion general equations
I The coaxial bodies system motion
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
cos sinP
P Q M Q
The coaxial top
I2 The angular motion equations of the magnetic DSSC and the coaxial Lagrange top
16
The single dipole model of the Earthrsquos magnetic field and the constant magnetic field vector corresponding to the circle equatorial orbit
The magnetic DSSC coordinate frames
17I3 The equations
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
2 2 2
2 1
0
T
x y zOx y z
T
orb orb
M M M
B m B m
oθ
θ
rbM m B
M
1 2
2 2
3 2
cos
cos
cos
OZ Ox
OZ Oy
OZ Oz
i k
j k
k k
2 2
2 1
2
0
Ap C B qr q Q
Bq A C pr p Q
C r B A pq M
orbQ B m
1
22 2 2 2 22
1 2 1 2 1 2
sin cos 1
2 2
T P
LI L l lT
A A A B C C
H H
cos sinP
P Q M Q
(6)
(5)
(4)
(3)
(2)
(1)
18I4 The integrals and solutions
2
2
2
1
2
23
x
y
z
K Ap
K KK Bq
K KK C r
K K
2
2
2
2 3
2
const
cos
z
z
L K C r
I I K
K C rL
K K K
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
2
2 2 22 2
1
2 2Ap Bq C r E C r TC
22 2 2 2 22 2A p B q C r K DT
2 1 2
22 21
2
22 2
Bq A C f q f q
C B C Ff q V E
A A B A A B
H B A B qf q V V
C A C
- AV Doroshin Exact Solutions in Attitude Dynamics of a Magnetic Dual-Spin Spacecraft and a Generalization of the Lagrange Top WSEAS Transactions on Systems Issue 10 Volume 12 (2013)
471-482
(11) (10)
(9)
(8) (7)
19I5 The analytical solution
The polhodes ellipsoid
2
2 2
22 2
2 1
1
1
q t H C A C x t SB A B
p t C B C x t FA A B
EAr t x t S t r t
A C C
2 20 0
2 20 0
sn
sn
i
i
R P c N t t I kx t e
R P c N t t I k
S E
The numerical integration (lines) and analytical (points) results
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075 q0=2 r0=583 [1s] K=50
[kgm2s] Q=100 [kgm2s2]
5
(13)
(12)
20I6 The analytical solution for Euler angles
orbB
K2K + ω timesK = mtimesK
K + ΩtimesK = 0
orbB
K 2Ω ω m
γ + Ωtimes γ = 0
1
2
3 2
t Ap t K
t Bq t K
C r t K
2cos
tg
t C r t K
Ap tt
Bq t
0
0
2 2
0 2 2 2 2
01
( ) ( )
( ) ( )
( )
t
t
t
t
Ap t Bq tt K dt
A p t B q t
t r t dtC
5
10 20 3003 052 08
The numerical integration (lines) and analytical (points) results for the directional cosines
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075
q0=2 r0=583 [1s] K=50 [km2s]
Q=100 [kgm2s2]
(19)
(20)
(18) (17)
(16)
(15)
(14)
21I7 Hamilton form of equations in the Andoyer-Deprit variables
(21)
(25)
(22)
(23)
(24)
1 C r
22
3 23
T T
T
L I Kl
I L I
K k K s K
K k
2
2
2
2 22
2 22
2
sin
cos
x
y
z
K Ap I L l
K Bq I L l
K C r L
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
22 2 2 2 22
1 2 1 2 1 2 2
sin cos 1
2 2
LI L l l LQ
A A A B C C I
H
22
(26)
Hamilton form of equations 2 2 2 1 1A B C A C
Equations (21) have heteroclinic solutions
Perturbations
0 0 L lM t f l t L t g t t dt
Melnikov function
(28)
The Melnikov function has the infinite number of simple roots This proves the fact of the motion chaotization at the presence of small harmonic perturbations
22 2 2 2
2 1
C B C EB
p t y t q t s k y t E r t y t t r tA A B B C C
0
sin cosN
n p n pn
Q t a n t b n t
22 2 2 2 2
20 0
1 2 1 2 1 2 2 20 1 0 1
sin cos 1
2 2
LI L l l L LQ Q Q t
A A A B C C I I
H H H H H
0 0 1 1
L L
L l L l
l l
L f l L gf f g g
l L l Ll f l L g
H H H H
0 0 00
cos sinN
ns n p n p
n
M t J a n t b n t
(27)
(26)
00 0 2
2
00 1 2 02
4 exp
exp 4
M aa E y t
ky t
Mt aE y a a a
k
23
2 l L I
I8 Numerical modeling Poincareacute sections mod 2 0pt
2 22 2 2 1 1 2 1 3 5
0 0 0 0
15 10 6 5 4[ ] 20 5 [ ] 075 [1 ] 1 5 20 [1]
) 5 004 ) 5 01 ) 10 01 ) 15 02
pA B C A C kg m I kg m s s a a a
a Q b Q c Q d Q
(a) (b)
(c) (d)
II The spider-type systems motion 24
m r K K K
1 2
3 4
5 6
4 2 m r
Ap p
Bq J I q I
Cr r
K K
ed
dt
Kω K M
12 56 34
34 12 56
56 34 12
ex
ey
ez
Ap I C B qr I q r M
Bq I A C pr I r p M
Cr I B A pq I p q M
4 2
4 2 4 2
iji j A A J I
B B J I C C J I
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i ex x
i e i ey y
i e i ez z
I p M M I p M M
I q M M I q M M
I r M M I r M M
(1)
(2)
(3)
(4)
II1 Angular momentum of the system in projections onto axes of the frame Oxyz
II2 The motion equations of the multirotor system
25
1 1
1 1
4 2
4 2 4 2
N Nij
il jl ll l
N N
l ll l
A A J NI
B B J NI C C J NI
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i el l lx l l lx
i e i el l ly l l ly
i e i el l lz l l lz
I p M M I p M M
I q M M I q M M
I r M M I r M M
0
1
2
3
cos 2
cos sin2
cos sin2
cos sin2
2 λ Θ λ
0
1
2
3
0
0
0
0
p q r
p r q
q r p
r q p
λ Θ
(4rsquo)
II3 The Euler parameters
(5)
26II4 The conjugate spinups and captures
Def1 Conjugate rotors are paired rotors located in the same layer on the opposite rays For example rotor 3N and rotor 4N are conjugate rotors (also rotor 12 and rotor 22 etc)
Def2 Conjugate spinup mean a process of spinning up conjugate rotors in opposite directions up to a desired value of relative angular velocity with the help of internal moments from main body Velocities of conjugate rotors will be equal in absolute value and opposite in sign
Def3 Rotor capture is an immediate deceleration of rotor relative angular velocity with the help of internal moment from the main body So rotor capture means an ldquoinstantaneous freezingrdquo of rotor with respect to the main body The capture can be performed with the help of gear meshing friction clutch or other methods
27
(6)
II6 Analytical solutions of motion equations
0e e ex y zM M M
A B C D
12 121
12 122
0
0
0
0
si
si
M if t tM
otherwise
M if t tM
otherwise
12 12 12sS M t I
1 12 2 12S S
1 1 12c c st t t
1 0
12
122
ISp
A IAS
A I
1 0 Conjugate spinup of rotors 1 2
Rotor 1 capture
Rotor 2 capture
2 2 1c c ct t t
1 2
121 2
0 0
c c
c c
t t tp IS
P t t tA I
Two serial captures of conjugate rotors bring to piecewise constant angular velocity of the main body
The main body performed the rotation about Ox axis by finite angle 12 2 1
c c
x
IS t t
A I
28
1 3 5 2 4 6
0 1 2 3
1 0
c c c c c c c cstart finish
c c c cstart start start start
t t t t t t t t
t t t t
0 1
2 3
2 2 2
cos sin2 2
sin sin2 2
c cstart start
c cstart start
c c c cstart finish finish start
t t t tPt t
t t t tQ Rt t
P Q R t t t T t t
1 2 t t t p P q Q r R
Letrsquos assume synchronically captures of coresponded conjugate rotors 1 2 3 4 5 6 and coincidence of the frame Oxyz initial position and the fixed frame OXYZ
Angular velocities between conjugate captures of rotors
Solutions of kinematic equations (5)
cos cos cosT
P Q R
T
e
The main body performed finite rotation about vector e by angle χ
(18)
(20)
(19)
(21)
29II7 Numerical simulation of reorientation process
const 0 1 135 246
i s cj jj j j
i s cj jj j j
jj
M M H t H t t H t t
M M H t H t t H t t
M j j
Two sets of results of numerical simulation
1 4 5(0) (0) (0) 0 (0) 100 1 s ω
ν = 300 Nms
H(t) is Heaviside function
FigA - zero value of angular momentum and different inertia moments of main body
Fig A Fig B
Fig4 - reorientation process at nonzero system angular momentum
30
__________________________________________________________
The main properties of the attitude stabilization and control of SC (and multirotor systems) have been examined
Research into attitude motion of the one-body-SC dual-spin SC and spider-type-SC is very complicated
Nontrivial and chaotic modes are possible in the SC attitude motion
Conclusion
- Slide 1
- Outline
- Part 1 - Introduction to Attitude Dynamics and Control
- Slide 4
- Spin stabilization
- Spin Stabilization Dual-Spin Spacecraft
- Spin Stabilization Dual-Spin Spacecraft (2)
- Spin Stabilization Dual-Spin Spacecraft (3)
- Spin Stabilization Dual-Spin Spacecraft (4)
- Gravity Gradient Stabilization
- Magnetic Stabilization
- Aerodynamic Stabilization
- Actuators
- Actuators (2)
- Actuators (3)
- Main Equations of Angular Motion of Rigid Body (Attitude Motion
- Main Properties of the Free Angular Motion of Rigid Body (Attit
- Main Properties of the Free Angular Motion of Rigid Body (Attit (2)
- Part 2 ndash Research Results
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
-
Spin StabilizationDual-Spin Spacecraft
4
HS 376Class Communications Nation USA
Mass 654 kg at beginning-of-life in geosynchronous orbit
Spin stabilized at 50 rpm by 4 hydrazine thrusters with 136 kg propellant Star 30 apogee kick motor Solar cells mounted on outside of cylindrical satellite body provide 990 W of power and recharge two NiCd batteries 24 + 6 backup 9 W transmission beams
HS 376 Chronology- 15 November 1980 SBS 1 Program- hellip- 22 November 1998 BONUM-1 Program
Spin StabilizationDual-Spin Spacecraft
4
Hughes HS-389
Intelsat-6 [Boeing] SDS-2 [NRO]
Ordered Date
Intelsat 601 1982 29101991
Intelsat 602 1982 27101989
Intelsat 603 1982 14031990
Intelsat 604 1982 23061990
Intelsat 605 1982 14081991
SDS-2 1 08081989
SDS-2 2 15111990
SDS-2 3 02121992
SDS-2 4 03071996
Gravity Gradient Stabilization 5
UniCubeSat-GG is the first CubeSat mission of GAUSS (Gruppo di Astrodinamica dell Universita degli Studi ldquola Sapienzardquo) at the University of Rome (Universita di Roma ldquoLa Sapienzardquo Scuola di Ingegneria Aerospaziale) Italy
The Gravity-gradient stabilization is a method of SC stabilizing in a fixed orientation using only the orbited bodys mass distribution and the Earths gravitational field
SC is placed along the radius-vector of the Earth
Tether-satellitesPhysical pendulums
Magnetic Stabilization 6
Magnetic stabilization is a method of SC stabilizing using geomagnetic field of the Earth
SC is positioned along the magnetic lines of the geomagnetic field (ldquomagnetic compassrdquo)
One of Four Alinco-5 Permanent Magnet sets on board KySat-1
KySat-1 Passive Magnetic Stabilization System is used for antenna orientation and coarse camera pointing
KySat-1 the first satellite project by Kentucky Space is a 1-U CubeSat scheduled to launch in 2010 on a NASA mission
Aerodynamic Stabilization 7
The Aerodynamic stabilization is a method of SC stabilizing using aerodynamic force in rarefied atmosphere of low earth orbit
SC is positioned along the orbital velocity vector
Aerodynamically Stable CubeSat Design Concept
ldquogo like an arrow helliprdquo
SC with tail unit
Actuators 8Reaction Wheel Assemblies (RWAs)
RWAs are particularly useful when the spacecraft must be rotated by very small amounts such as keeping a telescope pointed at a star
This is accomplished by equipping the spacecraft with an electric motor attached to a flywheel which when rotated increasingly fast causes the spacecraft to spin the other way in a proportional amount by conservation of angular momentum
Actuators 9Control Moment Gyros (CMGs)
A CMG consists of a spinning rotor and one or more motorized gimbals that tilt the rotorrsquos angular momentum As the rotor tilts the changing angular momentum causes a gyroscopic torque that rotates the spacecraft
Microsatellite with four control moment gyroscopes
Actuators 10Thrusters
A thruster is a small propulsive device used by spacecraft for attitude control in the reaction control system or long-duration low-thrust acceleration
Liquefied gases in high-pressure balloons
Main Equations of Angular Motion of Rigid Body(Attitude Motion of SC)
11
Euler dynamical equations
Euler kinematical equations
The study of the angular motion of the SC attitude dynamics is one of the main problems of rigid body systems dynamics in the classical mechanics
And vice versa
Tasks of analysis and synthesis of the rigid bodiesrsquo motion have important applications in the space-flight dynamics
Main Properties of the Free Angular Motion of Rigid Body(Attitude Motion of SC)
12
Louis Poinsot interpreacutetation
Inertia tensor with polhodes
--- notation by CDHall
Main Properties of the Free Angular Motion of Rigid Body(Attitude Motion of SC)
12
If we consider rigid body angular motion on the base of Hamilton dynamics than for rigid body motion we take pendulum phase structure
x=tetta (nutation) and
y = impulse (tetta) ~ d(tetta)dt
Pendulum phase space
Part 2 ndash Research Results
1 The magnetized dual-spin spacecraft attitude motion
2 The regular and chaotic dynamics of dual-spin spacecraft
3 The multi-rotor system and multi-spin spacecraft dynamics
13
14
Letrsquos consider an angular motion (about point O) of spider-type multiple rotor rigid bodies systems and
coaxial bodies systems
Mechanical models of multiple-rotor systems
Coaxial bodies system(dual-spin spacecraft)
Multirotor spiders(gyrostat-spacecrafts)
Number of rotors = N
Number of rotors = 6 Number of rotors = 1
1cos sin
cos
sin cos
sincos sin
cos
p q
p q
r p q
(1)
(2)
15
I1 The angular motion general equations
I The coaxial bodies system motion
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
cos sinP
P Q M Q
The coaxial top
I2 The angular motion equations of the magnetic DSSC and the coaxial Lagrange top
16
The single dipole model of the Earthrsquos magnetic field and the constant magnetic field vector corresponding to the circle equatorial orbit
The magnetic DSSC coordinate frames
17I3 The equations
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
2 2 2
2 1
0
T
x y zOx y z
T
orb orb
M M M
B m B m
oθ
θ
rbM m B
M
1 2
2 2
3 2
cos
cos
cos
OZ Ox
OZ Oy
OZ Oz
i k
j k
k k
2 2
2 1
2
0
Ap C B qr q Q
Bq A C pr p Q
C r B A pq M
orbQ B m
1
22 2 2 2 22
1 2 1 2 1 2
sin cos 1
2 2
T P
LI L l lT
A A A B C C
H H
cos sinP
P Q M Q
(6)
(5)
(4)
(3)
(2)
(1)
18I4 The integrals and solutions
2
2
2
1
2
23
x
y
z
K Ap
K KK Bq
K KK C r
K K
2
2
2
2 3
2
const
cos
z
z
L K C r
I I K
K C rL
K K K
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
2
2 2 22 2
1
2 2Ap Bq C r E C r TC
22 2 2 2 22 2A p B q C r K DT
2 1 2
22 21
2
22 2
Bq A C f q f q
C B C Ff q V E
A A B A A B
H B A B qf q V V
C A C
- AV Doroshin Exact Solutions in Attitude Dynamics of a Magnetic Dual-Spin Spacecraft and a Generalization of the Lagrange Top WSEAS Transactions on Systems Issue 10 Volume 12 (2013)
471-482
(11) (10)
(9)
(8) (7)
19I5 The analytical solution
The polhodes ellipsoid
2
2 2
22 2
2 1
1
1
q t H C A C x t SB A B
p t C B C x t FA A B
EAr t x t S t r t
A C C
2 20 0
2 20 0
sn
sn
i
i
R P c N t t I kx t e
R P c N t t I k
S E
The numerical integration (lines) and analytical (points) results
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075 q0=2 r0=583 [1s] K=50
[kgm2s] Q=100 [kgm2s2]
5
(13)
(12)
20I6 The analytical solution for Euler angles
orbB
K2K + ω timesK = mtimesK
K + ΩtimesK = 0
orbB
K 2Ω ω m
γ + Ωtimes γ = 0
1
2
3 2
t Ap t K
t Bq t K
C r t K
2cos
tg
t C r t K
Ap tt
Bq t
0
0
2 2
0 2 2 2 2
01
( ) ( )
( ) ( )
( )
t
t
t
t
Ap t Bq tt K dt
A p t B q t
t r t dtC
5
10 20 3003 052 08
The numerical integration (lines) and analytical (points) results for the directional cosines
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075
q0=2 r0=583 [1s] K=50 [km2s]
Q=100 [kgm2s2]
(19)
(20)
(18) (17)
(16)
(15)
(14)
21I7 Hamilton form of equations in the Andoyer-Deprit variables
(21)
(25)
(22)
(23)
(24)
1 C r
22
3 23
T T
T
L I Kl
I L I
K k K s K
K k
2
2
2
2 22
2 22
2
sin
cos
x
y
z
K Ap I L l
K Bq I L l
K C r L
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
22 2 2 2 22
1 2 1 2 1 2 2
sin cos 1
2 2
LI L l l LQ
A A A B C C I
H
22
(26)
Hamilton form of equations 2 2 2 1 1A B C A C
Equations (21) have heteroclinic solutions
Perturbations
0 0 L lM t f l t L t g t t dt
Melnikov function
(28)
The Melnikov function has the infinite number of simple roots This proves the fact of the motion chaotization at the presence of small harmonic perturbations
22 2 2 2
2 1
C B C EB
p t y t q t s k y t E r t y t t r tA A B B C C
0
sin cosN
n p n pn
Q t a n t b n t
22 2 2 2 2
20 0
1 2 1 2 1 2 2 20 1 0 1
sin cos 1
2 2
LI L l l L LQ Q Q t
A A A B C C I I
H H H H H
0 0 1 1
L L
L l L l
l l
L f l L gf f g g
l L l Ll f l L g
H H H H
0 0 00
cos sinN
ns n p n p
n
M t J a n t b n t
(27)
(26)
00 0 2
2
00 1 2 02
4 exp
exp 4
M aa E y t
ky t
Mt aE y a a a
k
23
2 l L I
I8 Numerical modeling Poincareacute sections mod 2 0pt
2 22 2 2 1 1 2 1 3 5
0 0 0 0
15 10 6 5 4[ ] 20 5 [ ] 075 [1 ] 1 5 20 [1]
) 5 004 ) 5 01 ) 10 01 ) 15 02
pA B C A C kg m I kg m s s a a a
a Q b Q c Q d Q
(a) (b)
(c) (d)
II The spider-type systems motion 24
m r K K K
1 2
3 4
5 6
4 2 m r
Ap p
Bq J I q I
Cr r
K K
ed
dt
Kω K M
12 56 34
34 12 56
56 34 12
ex
ey
ez
Ap I C B qr I q r M
Bq I A C pr I r p M
Cr I B A pq I p q M
4 2
4 2 4 2
iji j A A J I
B B J I C C J I
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i ex x
i e i ey y
i e i ez z
I p M M I p M M
I q M M I q M M
I r M M I r M M
(1)
(2)
(3)
(4)
II1 Angular momentum of the system in projections onto axes of the frame Oxyz
II2 The motion equations of the multirotor system
25
1 1
1 1
4 2
4 2 4 2
N Nij
il jl ll l
N N
l ll l
A A J NI
B B J NI C C J NI
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i el l lx l l lx
i e i el l ly l l ly
i e i el l lz l l lz
I p M M I p M M
I q M M I q M M
I r M M I r M M
0
1
2
3
cos 2
cos sin2
cos sin2
cos sin2
2 λ Θ λ
0
1
2
3
0
0
0
0
p q r
p r q
q r p
r q p
λ Θ
(4rsquo)
II3 The Euler parameters
(5)
26II4 The conjugate spinups and captures
Def1 Conjugate rotors are paired rotors located in the same layer on the opposite rays For example rotor 3N and rotor 4N are conjugate rotors (also rotor 12 and rotor 22 etc)
Def2 Conjugate spinup mean a process of spinning up conjugate rotors in opposite directions up to a desired value of relative angular velocity with the help of internal moments from main body Velocities of conjugate rotors will be equal in absolute value and opposite in sign
Def3 Rotor capture is an immediate deceleration of rotor relative angular velocity with the help of internal moment from the main body So rotor capture means an ldquoinstantaneous freezingrdquo of rotor with respect to the main body The capture can be performed with the help of gear meshing friction clutch or other methods
27
(6)
II6 Analytical solutions of motion equations
0e e ex y zM M M
A B C D
12 121
12 122
0
0
0
0
si
si
M if t tM
otherwise
M if t tM
otherwise
12 12 12sS M t I
1 12 2 12S S
1 1 12c c st t t
1 0
12
122
ISp
A IAS
A I
1 0 Conjugate spinup of rotors 1 2
Rotor 1 capture
Rotor 2 capture
2 2 1c c ct t t
1 2
121 2
0 0
c c
c c
t t tp IS
P t t tA I
Two serial captures of conjugate rotors bring to piecewise constant angular velocity of the main body
The main body performed the rotation about Ox axis by finite angle 12 2 1
c c
x
IS t t
A I
28
1 3 5 2 4 6
0 1 2 3
1 0
c c c c c c c cstart finish
c c c cstart start start start
t t t t t t t t
t t t t
0 1
2 3
2 2 2
cos sin2 2
sin sin2 2
c cstart start
c cstart start
c c c cstart finish finish start
t t t tPt t
t t t tQ Rt t
P Q R t t t T t t
1 2 t t t p P q Q r R
Letrsquos assume synchronically captures of coresponded conjugate rotors 1 2 3 4 5 6 and coincidence of the frame Oxyz initial position and the fixed frame OXYZ
Angular velocities between conjugate captures of rotors
Solutions of kinematic equations (5)
cos cos cosT
P Q R
T
e
The main body performed finite rotation about vector e by angle χ
(18)
(20)
(19)
(21)
29II7 Numerical simulation of reorientation process
const 0 1 135 246
i s cj jj j j
i s cj jj j j
jj
M M H t H t t H t t
M M H t H t t H t t
M j j
Two sets of results of numerical simulation
1 4 5(0) (0) (0) 0 (0) 100 1 s ω
ν = 300 Nms
H(t) is Heaviside function
FigA - zero value of angular momentum and different inertia moments of main body
Fig A Fig B
Fig4 - reorientation process at nonzero system angular momentum
30
__________________________________________________________
The main properties of the attitude stabilization and control of SC (and multirotor systems) have been examined
Research into attitude motion of the one-body-SC dual-spin SC and spider-type-SC is very complicated
Nontrivial and chaotic modes are possible in the SC attitude motion
Conclusion
- Slide 1
- Outline
- Part 1 - Introduction to Attitude Dynamics and Control
- Slide 4
- Spin stabilization
- Spin Stabilization Dual-Spin Spacecraft
- Spin Stabilization Dual-Spin Spacecraft (2)
- Spin Stabilization Dual-Spin Spacecraft (3)
- Spin Stabilization Dual-Spin Spacecraft (4)
- Gravity Gradient Stabilization
- Magnetic Stabilization
- Aerodynamic Stabilization
- Actuators
- Actuators (2)
- Actuators (3)
- Main Equations of Angular Motion of Rigid Body (Attitude Motion
- Main Properties of the Free Angular Motion of Rigid Body (Attit
- Main Properties of the Free Angular Motion of Rigid Body (Attit (2)
- Part 2 ndash Research Results
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
-
Spin StabilizationDual-Spin Spacecraft
4
Hughes HS-389
Intelsat-6 [Boeing] SDS-2 [NRO]
Ordered Date
Intelsat 601 1982 29101991
Intelsat 602 1982 27101989
Intelsat 603 1982 14031990
Intelsat 604 1982 23061990
Intelsat 605 1982 14081991
SDS-2 1 08081989
SDS-2 2 15111990
SDS-2 3 02121992
SDS-2 4 03071996
Gravity Gradient Stabilization 5
UniCubeSat-GG is the first CubeSat mission of GAUSS (Gruppo di Astrodinamica dell Universita degli Studi ldquola Sapienzardquo) at the University of Rome (Universita di Roma ldquoLa Sapienzardquo Scuola di Ingegneria Aerospaziale) Italy
The Gravity-gradient stabilization is a method of SC stabilizing in a fixed orientation using only the orbited bodys mass distribution and the Earths gravitational field
SC is placed along the radius-vector of the Earth
Tether-satellitesPhysical pendulums
Magnetic Stabilization 6
Magnetic stabilization is a method of SC stabilizing using geomagnetic field of the Earth
SC is positioned along the magnetic lines of the geomagnetic field (ldquomagnetic compassrdquo)
One of Four Alinco-5 Permanent Magnet sets on board KySat-1
KySat-1 Passive Magnetic Stabilization System is used for antenna orientation and coarse camera pointing
KySat-1 the first satellite project by Kentucky Space is a 1-U CubeSat scheduled to launch in 2010 on a NASA mission
Aerodynamic Stabilization 7
The Aerodynamic stabilization is a method of SC stabilizing using aerodynamic force in rarefied atmosphere of low earth orbit
SC is positioned along the orbital velocity vector
Aerodynamically Stable CubeSat Design Concept
ldquogo like an arrow helliprdquo
SC with tail unit
Actuators 8Reaction Wheel Assemblies (RWAs)
RWAs are particularly useful when the spacecraft must be rotated by very small amounts such as keeping a telescope pointed at a star
This is accomplished by equipping the spacecraft with an electric motor attached to a flywheel which when rotated increasingly fast causes the spacecraft to spin the other way in a proportional amount by conservation of angular momentum
Actuators 9Control Moment Gyros (CMGs)
A CMG consists of a spinning rotor and one or more motorized gimbals that tilt the rotorrsquos angular momentum As the rotor tilts the changing angular momentum causes a gyroscopic torque that rotates the spacecraft
Microsatellite with four control moment gyroscopes
Actuators 10Thrusters
A thruster is a small propulsive device used by spacecraft for attitude control in the reaction control system or long-duration low-thrust acceleration
Liquefied gases in high-pressure balloons
Main Equations of Angular Motion of Rigid Body(Attitude Motion of SC)
11
Euler dynamical equations
Euler kinematical equations
The study of the angular motion of the SC attitude dynamics is one of the main problems of rigid body systems dynamics in the classical mechanics
And vice versa
Tasks of analysis and synthesis of the rigid bodiesrsquo motion have important applications in the space-flight dynamics
Main Properties of the Free Angular Motion of Rigid Body(Attitude Motion of SC)
12
Louis Poinsot interpreacutetation
Inertia tensor with polhodes
--- notation by CDHall
Main Properties of the Free Angular Motion of Rigid Body(Attitude Motion of SC)
12
If we consider rigid body angular motion on the base of Hamilton dynamics than for rigid body motion we take pendulum phase structure
x=tetta (nutation) and
y = impulse (tetta) ~ d(tetta)dt
Pendulum phase space
Part 2 ndash Research Results
1 The magnetized dual-spin spacecraft attitude motion
2 The regular and chaotic dynamics of dual-spin spacecraft
3 The multi-rotor system and multi-spin spacecraft dynamics
13
14
Letrsquos consider an angular motion (about point O) of spider-type multiple rotor rigid bodies systems and
coaxial bodies systems
Mechanical models of multiple-rotor systems
Coaxial bodies system(dual-spin spacecraft)
Multirotor spiders(gyrostat-spacecrafts)
Number of rotors = N
Number of rotors = 6 Number of rotors = 1
1cos sin
cos
sin cos
sincos sin
cos
p q
p q
r p q
(1)
(2)
15
I1 The angular motion general equations
I The coaxial bodies system motion
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
cos sinP
P Q M Q
The coaxial top
I2 The angular motion equations of the magnetic DSSC and the coaxial Lagrange top
16
The single dipole model of the Earthrsquos magnetic field and the constant magnetic field vector corresponding to the circle equatorial orbit
The magnetic DSSC coordinate frames
17I3 The equations
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
2 2 2
2 1
0
T
x y zOx y z
T
orb orb
M M M
B m B m
oθ
θ
rbM m B
M
1 2
2 2
3 2
cos
cos
cos
OZ Ox
OZ Oy
OZ Oz
i k
j k
k k
2 2
2 1
2
0
Ap C B qr q Q
Bq A C pr p Q
C r B A pq M
orbQ B m
1
22 2 2 2 22
1 2 1 2 1 2
sin cos 1
2 2
T P
LI L l lT
A A A B C C
H H
cos sinP
P Q M Q
(6)
(5)
(4)
(3)
(2)
(1)
18I4 The integrals and solutions
2
2
2
1
2
23
x
y
z
K Ap
K KK Bq
K KK C r
K K
2
2
2
2 3
2
const
cos
z
z
L K C r
I I K
K C rL
K K K
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
2
2 2 22 2
1
2 2Ap Bq C r E C r TC
22 2 2 2 22 2A p B q C r K DT
2 1 2
22 21
2
22 2
Bq A C f q f q
C B C Ff q V E
A A B A A B
H B A B qf q V V
C A C
- AV Doroshin Exact Solutions in Attitude Dynamics of a Magnetic Dual-Spin Spacecraft and a Generalization of the Lagrange Top WSEAS Transactions on Systems Issue 10 Volume 12 (2013)
471-482
(11) (10)
(9)
(8) (7)
19I5 The analytical solution
The polhodes ellipsoid
2
2 2
22 2
2 1
1
1
q t H C A C x t SB A B
p t C B C x t FA A B
EAr t x t S t r t
A C C
2 20 0
2 20 0
sn
sn
i
i
R P c N t t I kx t e
R P c N t t I k
S E
The numerical integration (lines) and analytical (points) results
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075 q0=2 r0=583 [1s] K=50
[kgm2s] Q=100 [kgm2s2]
5
(13)
(12)
20I6 The analytical solution for Euler angles
orbB
K2K + ω timesK = mtimesK
K + ΩtimesK = 0
orbB
K 2Ω ω m
γ + Ωtimes γ = 0
1
2
3 2
t Ap t K
t Bq t K
C r t K
2cos
tg
t C r t K
Ap tt
Bq t
0
0
2 2
0 2 2 2 2
01
( ) ( )
( ) ( )
( )
t
t
t
t
Ap t Bq tt K dt
A p t B q t
t r t dtC
5
10 20 3003 052 08
The numerical integration (lines) and analytical (points) results for the directional cosines
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075
q0=2 r0=583 [1s] K=50 [km2s]
Q=100 [kgm2s2]
(19)
(20)
(18) (17)
(16)
(15)
(14)
21I7 Hamilton form of equations in the Andoyer-Deprit variables
(21)
(25)
(22)
(23)
(24)
1 C r
22
3 23
T T
T
L I Kl
I L I
K k K s K
K k
2
2
2
2 22
2 22
2
sin
cos
x
y
z
K Ap I L l
K Bq I L l
K C r L
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
22 2 2 2 22
1 2 1 2 1 2 2
sin cos 1
2 2
LI L l l LQ
A A A B C C I
H
22
(26)
Hamilton form of equations 2 2 2 1 1A B C A C
Equations (21) have heteroclinic solutions
Perturbations
0 0 L lM t f l t L t g t t dt
Melnikov function
(28)
The Melnikov function has the infinite number of simple roots This proves the fact of the motion chaotization at the presence of small harmonic perturbations
22 2 2 2
2 1
C B C EB
p t y t q t s k y t E r t y t t r tA A B B C C
0
sin cosN
n p n pn
Q t a n t b n t
22 2 2 2 2
20 0
1 2 1 2 1 2 2 20 1 0 1
sin cos 1
2 2
LI L l l L LQ Q Q t
A A A B C C I I
H H H H H
0 0 1 1
L L
L l L l
l l
L f l L gf f g g
l L l Ll f l L g
H H H H
0 0 00
cos sinN
ns n p n p
n
M t J a n t b n t
(27)
(26)
00 0 2
2
00 1 2 02
4 exp
exp 4
M aa E y t
ky t
Mt aE y a a a
k
23
2 l L I
I8 Numerical modeling Poincareacute sections mod 2 0pt
2 22 2 2 1 1 2 1 3 5
0 0 0 0
15 10 6 5 4[ ] 20 5 [ ] 075 [1 ] 1 5 20 [1]
) 5 004 ) 5 01 ) 10 01 ) 15 02
pA B C A C kg m I kg m s s a a a
a Q b Q c Q d Q
(a) (b)
(c) (d)
II The spider-type systems motion 24
m r K K K
1 2
3 4
5 6
4 2 m r
Ap p
Bq J I q I
Cr r
K K
ed
dt
Kω K M
12 56 34
34 12 56
56 34 12
ex
ey
ez
Ap I C B qr I q r M
Bq I A C pr I r p M
Cr I B A pq I p q M
4 2
4 2 4 2
iji j A A J I
B B J I C C J I
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i ex x
i e i ey y
i e i ez z
I p M M I p M M
I q M M I q M M
I r M M I r M M
(1)
(2)
(3)
(4)
II1 Angular momentum of the system in projections onto axes of the frame Oxyz
II2 The motion equations of the multirotor system
25
1 1
1 1
4 2
4 2 4 2
N Nij
il jl ll l
N N
l ll l
A A J NI
B B J NI C C J NI
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i el l lx l l lx
i e i el l ly l l ly
i e i el l lz l l lz
I p M M I p M M
I q M M I q M M
I r M M I r M M
0
1
2
3
cos 2
cos sin2
cos sin2
cos sin2
2 λ Θ λ
0
1
2
3
0
0
0
0
p q r
p r q
q r p
r q p
λ Θ
(4rsquo)
II3 The Euler parameters
(5)
26II4 The conjugate spinups and captures
Def1 Conjugate rotors are paired rotors located in the same layer on the opposite rays For example rotor 3N and rotor 4N are conjugate rotors (also rotor 12 and rotor 22 etc)
Def2 Conjugate spinup mean a process of spinning up conjugate rotors in opposite directions up to a desired value of relative angular velocity with the help of internal moments from main body Velocities of conjugate rotors will be equal in absolute value and opposite in sign
Def3 Rotor capture is an immediate deceleration of rotor relative angular velocity with the help of internal moment from the main body So rotor capture means an ldquoinstantaneous freezingrdquo of rotor with respect to the main body The capture can be performed with the help of gear meshing friction clutch or other methods
27
(6)
II6 Analytical solutions of motion equations
0e e ex y zM M M
A B C D
12 121
12 122
0
0
0
0
si
si
M if t tM
otherwise
M if t tM
otherwise
12 12 12sS M t I
1 12 2 12S S
1 1 12c c st t t
1 0
12
122
ISp
A IAS
A I
1 0 Conjugate spinup of rotors 1 2
Rotor 1 capture
Rotor 2 capture
2 2 1c c ct t t
1 2
121 2
0 0
c c
c c
t t tp IS
P t t tA I
Two serial captures of conjugate rotors bring to piecewise constant angular velocity of the main body
The main body performed the rotation about Ox axis by finite angle 12 2 1
c c
x
IS t t
A I
28
1 3 5 2 4 6
0 1 2 3
1 0
c c c c c c c cstart finish
c c c cstart start start start
t t t t t t t t
t t t t
0 1
2 3
2 2 2
cos sin2 2
sin sin2 2
c cstart start
c cstart start
c c c cstart finish finish start
t t t tPt t
t t t tQ Rt t
P Q R t t t T t t
1 2 t t t p P q Q r R
Letrsquos assume synchronically captures of coresponded conjugate rotors 1 2 3 4 5 6 and coincidence of the frame Oxyz initial position and the fixed frame OXYZ
Angular velocities between conjugate captures of rotors
Solutions of kinematic equations (5)
cos cos cosT
P Q R
T
e
The main body performed finite rotation about vector e by angle χ
(18)
(20)
(19)
(21)
29II7 Numerical simulation of reorientation process
const 0 1 135 246
i s cj jj j j
i s cj jj j j
jj
M M H t H t t H t t
M M H t H t t H t t
M j j
Two sets of results of numerical simulation
1 4 5(0) (0) (0) 0 (0) 100 1 s ω
ν = 300 Nms
H(t) is Heaviside function
FigA - zero value of angular momentum and different inertia moments of main body
Fig A Fig B
Fig4 - reorientation process at nonzero system angular momentum
30
__________________________________________________________
The main properties of the attitude stabilization and control of SC (and multirotor systems) have been examined
Research into attitude motion of the one-body-SC dual-spin SC and spider-type-SC is very complicated
Nontrivial and chaotic modes are possible in the SC attitude motion
Conclusion
- Slide 1
- Outline
- Part 1 - Introduction to Attitude Dynamics and Control
- Slide 4
- Spin stabilization
- Spin Stabilization Dual-Spin Spacecraft
- Spin Stabilization Dual-Spin Spacecraft (2)
- Spin Stabilization Dual-Spin Spacecraft (3)
- Spin Stabilization Dual-Spin Spacecraft (4)
- Gravity Gradient Stabilization
- Magnetic Stabilization
- Aerodynamic Stabilization
- Actuators
- Actuators (2)
- Actuators (3)
- Main Equations of Angular Motion of Rigid Body (Attitude Motion
- Main Properties of the Free Angular Motion of Rigid Body (Attit
- Main Properties of the Free Angular Motion of Rigid Body (Attit (2)
- Part 2 ndash Research Results
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
-
Gravity Gradient Stabilization 5
UniCubeSat-GG is the first CubeSat mission of GAUSS (Gruppo di Astrodinamica dell Universita degli Studi ldquola Sapienzardquo) at the University of Rome (Universita di Roma ldquoLa Sapienzardquo Scuola di Ingegneria Aerospaziale) Italy
The Gravity-gradient stabilization is a method of SC stabilizing in a fixed orientation using only the orbited bodys mass distribution and the Earths gravitational field
SC is placed along the radius-vector of the Earth
Tether-satellitesPhysical pendulums
Magnetic Stabilization 6
Magnetic stabilization is a method of SC stabilizing using geomagnetic field of the Earth
SC is positioned along the magnetic lines of the geomagnetic field (ldquomagnetic compassrdquo)
One of Four Alinco-5 Permanent Magnet sets on board KySat-1
KySat-1 Passive Magnetic Stabilization System is used for antenna orientation and coarse camera pointing
KySat-1 the first satellite project by Kentucky Space is a 1-U CubeSat scheduled to launch in 2010 on a NASA mission
Aerodynamic Stabilization 7
The Aerodynamic stabilization is a method of SC stabilizing using aerodynamic force in rarefied atmosphere of low earth orbit
SC is positioned along the orbital velocity vector
Aerodynamically Stable CubeSat Design Concept
ldquogo like an arrow helliprdquo
SC with tail unit
Actuators 8Reaction Wheel Assemblies (RWAs)
RWAs are particularly useful when the spacecraft must be rotated by very small amounts such as keeping a telescope pointed at a star
This is accomplished by equipping the spacecraft with an electric motor attached to a flywheel which when rotated increasingly fast causes the spacecraft to spin the other way in a proportional amount by conservation of angular momentum
Actuators 9Control Moment Gyros (CMGs)
A CMG consists of a spinning rotor and one or more motorized gimbals that tilt the rotorrsquos angular momentum As the rotor tilts the changing angular momentum causes a gyroscopic torque that rotates the spacecraft
Microsatellite with four control moment gyroscopes
Actuators 10Thrusters
A thruster is a small propulsive device used by spacecraft for attitude control in the reaction control system or long-duration low-thrust acceleration
Liquefied gases in high-pressure balloons
Main Equations of Angular Motion of Rigid Body(Attitude Motion of SC)
11
Euler dynamical equations
Euler kinematical equations
The study of the angular motion of the SC attitude dynamics is one of the main problems of rigid body systems dynamics in the classical mechanics
And vice versa
Tasks of analysis and synthesis of the rigid bodiesrsquo motion have important applications in the space-flight dynamics
Main Properties of the Free Angular Motion of Rigid Body(Attitude Motion of SC)
12
Louis Poinsot interpreacutetation
Inertia tensor with polhodes
--- notation by CDHall
Main Properties of the Free Angular Motion of Rigid Body(Attitude Motion of SC)
12
If we consider rigid body angular motion on the base of Hamilton dynamics than for rigid body motion we take pendulum phase structure
x=tetta (nutation) and
y = impulse (tetta) ~ d(tetta)dt
Pendulum phase space
Part 2 ndash Research Results
1 The magnetized dual-spin spacecraft attitude motion
2 The regular and chaotic dynamics of dual-spin spacecraft
3 The multi-rotor system and multi-spin spacecraft dynamics
13
14
Letrsquos consider an angular motion (about point O) of spider-type multiple rotor rigid bodies systems and
coaxial bodies systems
Mechanical models of multiple-rotor systems
Coaxial bodies system(dual-spin spacecraft)
Multirotor spiders(gyrostat-spacecrafts)
Number of rotors = N
Number of rotors = 6 Number of rotors = 1
1cos sin
cos
sin cos
sincos sin
cos
p q
p q
r p q
(1)
(2)
15
I1 The angular motion general equations
I The coaxial bodies system motion
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
cos sinP
P Q M Q
The coaxial top
I2 The angular motion equations of the magnetic DSSC and the coaxial Lagrange top
16
The single dipole model of the Earthrsquos magnetic field and the constant magnetic field vector corresponding to the circle equatorial orbit
The magnetic DSSC coordinate frames
17I3 The equations
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
2 2 2
2 1
0
T
x y zOx y z
T
orb orb
M M M
B m B m
oθ
θ
rbM m B
M
1 2
2 2
3 2
cos
cos
cos
OZ Ox
OZ Oy
OZ Oz
i k
j k
k k
2 2
2 1
2
0
Ap C B qr q Q
Bq A C pr p Q
C r B A pq M
orbQ B m
1
22 2 2 2 22
1 2 1 2 1 2
sin cos 1
2 2
T P
LI L l lT
A A A B C C
H H
cos sinP
P Q M Q
(6)
(5)
(4)
(3)
(2)
(1)
18I4 The integrals and solutions
2
2
2
1
2
23
x
y
z
K Ap
K KK Bq
K KK C r
K K
2
2
2
2 3
2
const
cos
z
z
L K C r
I I K
K C rL
K K K
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
2
2 2 22 2
1
2 2Ap Bq C r E C r TC
22 2 2 2 22 2A p B q C r K DT
2 1 2
22 21
2
22 2
Bq A C f q f q
C B C Ff q V E
A A B A A B
H B A B qf q V V
C A C
- AV Doroshin Exact Solutions in Attitude Dynamics of a Magnetic Dual-Spin Spacecraft and a Generalization of the Lagrange Top WSEAS Transactions on Systems Issue 10 Volume 12 (2013)
471-482
(11) (10)
(9)
(8) (7)
19I5 The analytical solution
The polhodes ellipsoid
2
2 2
22 2
2 1
1
1
q t H C A C x t SB A B
p t C B C x t FA A B
EAr t x t S t r t
A C C
2 20 0
2 20 0
sn
sn
i
i
R P c N t t I kx t e
R P c N t t I k
S E
The numerical integration (lines) and analytical (points) results
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075 q0=2 r0=583 [1s] K=50
[kgm2s] Q=100 [kgm2s2]
5
(13)
(12)
20I6 The analytical solution for Euler angles
orbB
K2K + ω timesK = mtimesK
K + ΩtimesK = 0
orbB
K 2Ω ω m
γ + Ωtimes γ = 0
1
2
3 2
t Ap t K
t Bq t K
C r t K
2cos
tg
t C r t K
Ap tt
Bq t
0
0
2 2
0 2 2 2 2
01
( ) ( )
( ) ( )
( )
t
t
t
t
Ap t Bq tt K dt
A p t B q t
t r t dtC
5
10 20 3003 052 08
The numerical integration (lines) and analytical (points) results for the directional cosines
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075
q0=2 r0=583 [1s] K=50 [km2s]
Q=100 [kgm2s2]
(19)
(20)
(18) (17)
(16)
(15)
(14)
21I7 Hamilton form of equations in the Andoyer-Deprit variables
(21)
(25)
(22)
(23)
(24)
1 C r
22
3 23
T T
T
L I Kl
I L I
K k K s K
K k
2
2
2
2 22
2 22
2
sin
cos
x
y
z
K Ap I L l
K Bq I L l
K C r L
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
22 2 2 2 22
1 2 1 2 1 2 2
sin cos 1
2 2
LI L l l LQ
A A A B C C I
H
22
(26)
Hamilton form of equations 2 2 2 1 1A B C A C
Equations (21) have heteroclinic solutions
Perturbations
0 0 L lM t f l t L t g t t dt
Melnikov function
(28)
The Melnikov function has the infinite number of simple roots This proves the fact of the motion chaotization at the presence of small harmonic perturbations
22 2 2 2
2 1
C B C EB
p t y t q t s k y t E r t y t t r tA A B B C C
0
sin cosN
n p n pn
Q t a n t b n t
22 2 2 2 2
20 0
1 2 1 2 1 2 2 20 1 0 1
sin cos 1
2 2
LI L l l L LQ Q Q t
A A A B C C I I
H H H H H
0 0 1 1
L L
L l L l
l l
L f l L gf f g g
l L l Ll f l L g
H H H H
0 0 00
cos sinN
ns n p n p
n
M t J a n t b n t
(27)
(26)
00 0 2
2
00 1 2 02
4 exp
exp 4
M aa E y t
ky t
Mt aE y a a a
k
23
2 l L I
I8 Numerical modeling Poincareacute sections mod 2 0pt
2 22 2 2 1 1 2 1 3 5
0 0 0 0
15 10 6 5 4[ ] 20 5 [ ] 075 [1 ] 1 5 20 [1]
) 5 004 ) 5 01 ) 10 01 ) 15 02
pA B C A C kg m I kg m s s a a a
a Q b Q c Q d Q
(a) (b)
(c) (d)
II The spider-type systems motion 24
m r K K K
1 2
3 4
5 6
4 2 m r
Ap p
Bq J I q I
Cr r
K K
ed
dt
Kω K M
12 56 34
34 12 56
56 34 12
ex
ey
ez
Ap I C B qr I q r M
Bq I A C pr I r p M
Cr I B A pq I p q M
4 2
4 2 4 2
iji j A A J I
B B J I C C J I
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i ex x
i e i ey y
i e i ez z
I p M M I p M M
I q M M I q M M
I r M M I r M M
(1)
(2)
(3)
(4)
II1 Angular momentum of the system in projections onto axes of the frame Oxyz
II2 The motion equations of the multirotor system
25
1 1
1 1
4 2
4 2 4 2
N Nij
il jl ll l
N N
l ll l
A A J NI
B B J NI C C J NI
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i el l lx l l lx
i e i el l ly l l ly
i e i el l lz l l lz
I p M M I p M M
I q M M I q M M
I r M M I r M M
0
1
2
3
cos 2
cos sin2
cos sin2
cos sin2
2 λ Θ λ
0
1
2
3
0
0
0
0
p q r
p r q
q r p
r q p
λ Θ
(4rsquo)
II3 The Euler parameters
(5)
26II4 The conjugate spinups and captures
Def1 Conjugate rotors are paired rotors located in the same layer on the opposite rays For example rotor 3N and rotor 4N are conjugate rotors (also rotor 12 and rotor 22 etc)
Def2 Conjugate spinup mean a process of spinning up conjugate rotors in opposite directions up to a desired value of relative angular velocity with the help of internal moments from main body Velocities of conjugate rotors will be equal in absolute value and opposite in sign
Def3 Rotor capture is an immediate deceleration of rotor relative angular velocity with the help of internal moment from the main body So rotor capture means an ldquoinstantaneous freezingrdquo of rotor with respect to the main body The capture can be performed with the help of gear meshing friction clutch or other methods
27
(6)
II6 Analytical solutions of motion equations
0e e ex y zM M M
A B C D
12 121
12 122
0
0
0
0
si
si
M if t tM
otherwise
M if t tM
otherwise
12 12 12sS M t I
1 12 2 12S S
1 1 12c c st t t
1 0
12
122
ISp
A IAS
A I
1 0 Conjugate spinup of rotors 1 2
Rotor 1 capture
Rotor 2 capture
2 2 1c c ct t t
1 2
121 2
0 0
c c
c c
t t tp IS
P t t tA I
Two serial captures of conjugate rotors bring to piecewise constant angular velocity of the main body
The main body performed the rotation about Ox axis by finite angle 12 2 1
c c
x
IS t t
A I
28
1 3 5 2 4 6
0 1 2 3
1 0
c c c c c c c cstart finish
c c c cstart start start start
t t t t t t t t
t t t t
0 1
2 3
2 2 2
cos sin2 2
sin sin2 2
c cstart start
c cstart start
c c c cstart finish finish start
t t t tPt t
t t t tQ Rt t
P Q R t t t T t t
1 2 t t t p P q Q r R
Letrsquos assume synchronically captures of coresponded conjugate rotors 1 2 3 4 5 6 and coincidence of the frame Oxyz initial position and the fixed frame OXYZ
Angular velocities between conjugate captures of rotors
Solutions of kinematic equations (5)
cos cos cosT
P Q R
T
e
The main body performed finite rotation about vector e by angle χ
(18)
(20)
(19)
(21)
29II7 Numerical simulation of reorientation process
const 0 1 135 246
i s cj jj j j
i s cj jj j j
jj
M M H t H t t H t t
M M H t H t t H t t
M j j
Two sets of results of numerical simulation
1 4 5(0) (0) (0) 0 (0) 100 1 s ω
ν = 300 Nms
H(t) is Heaviside function
FigA - zero value of angular momentum and different inertia moments of main body
Fig A Fig B
Fig4 - reorientation process at nonzero system angular momentum
30
__________________________________________________________
The main properties of the attitude stabilization and control of SC (and multirotor systems) have been examined
Research into attitude motion of the one-body-SC dual-spin SC and spider-type-SC is very complicated
Nontrivial and chaotic modes are possible in the SC attitude motion
Conclusion
- Slide 1
- Outline
- Part 1 - Introduction to Attitude Dynamics and Control
- Slide 4
- Spin stabilization
- Spin Stabilization Dual-Spin Spacecraft
- Spin Stabilization Dual-Spin Spacecraft (2)
- Spin Stabilization Dual-Spin Spacecraft (3)
- Spin Stabilization Dual-Spin Spacecraft (4)
- Gravity Gradient Stabilization
- Magnetic Stabilization
- Aerodynamic Stabilization
- Actuators
- Actuators (2)
- Actuators (3)
- Main Equations of Angular Motion of Rigid Body (Attitude Motion
- Main Properties of the Free Angular Motion of Rigid Body (Attit
- Main Properties of the Free Angular Motion of Rigid Body (Attit (2)
- Part 2 ndash Research Results
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
-
Magnetic Stabilization 6
Magnetic stabilization is a method of SC stabilizing using geomagnetic field of the Earth
SC is positioned along the magnetic lines of the geomagnetic field (ldquomagnetic compassrdquo)
One of Four Alinco-5 Permanent Magnet sets on board KySat-1
KySat-1 Passive Magnetic Stabilization System is used for antenna orientation and coarse camera pointing
KySat-1 the first satellite project by Kentucky Space is a 1-U CubeSat scheduled to launch in 2010 on a NASA mission
Aerodynamic Stabilization 7
The Aerodynamic stabilization is a method of SC stabilizing using aerodynamic force in rarefied atmosphere of low earth orbit
SC is positioned along the orbital velocity vector
Aerodynamically Stable CubeSat Design Concept
ldquogo like an arrow helliprdquo
SC with tail unit
Actuators 8Reaction Wheel Assemblies (RWAs)
RWAs are particularly useful when the spacecraft must be rotated by very small amounts such as keeping a telescope pointed at a star
This is accomplished by equipping the spacecraft with an electric motor attached to a flywheel which when rotated increasingly fast causes the spacecraft to spin the other way in a proportional amount by conservation of angular momentum
Actuators 9Control Moment Gyros (CMGs)
A CMG consists of a spinning rotor and one or more motorized gimbals that tilt the rotorrsquos angular momentum As the rotor tilts the changing angular momentum causes a gyroscopic torque that rotates the spacecraft
Microsatellite with four control moment gyroscopes
Actuators 10Thrusters
A thruster is a small propulsive device used by spacecraft for attitude control in the reaction control system or long-duration low-thrust acceleration
Liquefied gases in high-pressure balloons
Main Equations of Angular Motion of Rigid Body(Attitude Motion of SC)
11
Euler dynamical equations
Euler kinematical equations
The study of the angular motion of the SC attitude dynamics is one of the main problems of rigid body systems dynamics in the classical mechanics
And vice versa
Tasks of analysis and synthesis of the rigid bodiesrsquo motion have important applications in the space-flight dynamics
Main Properties of the Free Angular Motion of Rigid Body(Attitude Motion of SC)
12
Louis Poinsot interpreacutetation
Inertia tensor with polhodes
--- notation by CDHall
Main Properties of the Free Angular Motion of Rigid Body(Attitude Motion of SC)
12
If we consider rigid body angular motion on the base of Hamilton dynamics than for rigid body motion we take pendulum phase structure
x=tetta (nutation) and
y = impulse (tetta) ~ d(tetta)dt
Pendulum phase space
Part 2 ndash Research Results
1 The magnetized dual-spin spacecraft attitude motion
2 The regular and chaotic dynamics of dual-spin spacecraft
3 The multi-rotor system and multi-spin spacecraft dynamics
13
14
Letrsquos consider an angular motion (about point O) of spider-type multiple rotor rigid bodies systems and
coaxial bodies systems
Mechanical models of multiple-rotor systems
Coaxial bodies system(dual-spin spacecraft)
Multirotor spiders(gyrostat-spacecrafts)
Number of rotors = N
Number of rotors = 6 Number of rotors = 1
1cos sin
cos
sin cos
sincos sin
cos
p q
p q
r p q
(1)
(2)
15
I1 The angular motion general equations
I The coaxial bodies system motion
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
cos sinP
P Q M Q
The coaxial top
I2 The angular motion equations of the magnetic DSSC and the coaxial Lagrange top
16
The single dipole model of the Earthrsquos magnetic field and the constant magnetic field vector corresponding to the circle equatorial orbit
The magnetic DSSC coordinate frames
17I3 The equations
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
2 2 2
2 1
0
T
x y zOx y z
T
orb orb
M M M
B m B m
oθ
θ
rbM m B
M
1 2
2 2
3 2
cos
cos
cos
OZ Ox
OZ Oy
OZ Oz
i k
j k
k k
2 2
2 1
2
0
Ap C B qr q Q
Bq A C pr p Q
C r B A pq M
orbQ B m
1
22 2 2 2 22
1 2 1 2 1 2
sin cos 1
2 2
T P
LI L l lT
A A A B C C
H H
cos sinP
P Q M Q
(6)
(5)
(4)
(3)
(2)
(1)
18I4 The integrals and solutions
2
2
2
1
2
23
x
y
z
K Ap
K KK Bq
K KK C r
K K
2
2
2
2 3
2
const
cos
z
z
L K C r
I I K
K C rL
K K K
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
2
2 2 22 2
1
2 2Ap Bq C r E C r TC
22 2 2 2 22 2A p B q C r K DT
2 1 2
22 21
2
22 2
Bq A C f q f q
C B C Ff q V E
A A B A A B
H B A B qf q V V
C A C
- AV Doroshin Exact Solutions in Attitude Dynamics of a Magnetic Dual-Spin Spacecraft and a Generalization of the Lagrange Top WSEAS Transactions on Systems Issue 10 Volume 12 (2013)
471-482
(11) (10)
(9)
(8) (7)
19I5 The analytical solution
The polhodes ellipsoid
2
2 2
22 2
2 1
1
1
q t H C A C x t SB A B
p t C B C x t FA A B
EAr t x t S t r t
A C C
2 20 0
2 20 0
sn
sn
i
i
R P c N t t I kx t e
R P c N t t I k
S E
The numerical integration (lines) and analytical (points) results
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075 q0=2 r0=583 [1s] K=50
[kgm2s] Q=100 [kgm2s2]
5
(13)
(12)
20I6 The analytical solution for Euler angles
orbB
K2K + ω timesK = mtimesK
K + ΩtimesK = 0
orbB
K 2Ω ω m
γ + Ωtimes γ = 0
1
2
3 2
t Ap t K
t Bq t K
C r t K
2cos
tg
t C r t K
Ap tt
Bq t
0
0
2 2
0 2 2 2 2
01
( ) ( )
( ) ( )
( )
t
t
t
t
Ap t Bq tt K dt
A p t B q t
t r t dtC
5
10 20 3003 052 08
The numerical integration (lines) and analytical (points) results for the directional cosines
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075
q0=2 r0=583 [1s] K=50 [km2s]
Q=100 [kgm2s2]
(19)
(20)
(18) (17)
(16)
(15)
(14)
21I7 Hamilton form of equations in the Andoyer-Deprit variables
(21)
(25)
(22)
(23)
(24)
1 C r
22
3 23
T T
T
L I Kl
I L I
K k K s K
K k
2
2
2
2 22
2 22
2
sin
cos
x
y
z
K Ap I L l
K Bq I L l
K C r L
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
22 2 2 2 22
1 2 1 2 1 2 2
sin cos 1
2 2
LI L l l LQ
A A A B C C I
H
22
(26)
Hamilton form of equations 2 2 2 1 1A B C A C
Equations (21) have heteroclinic solutions
Perturbations
0 0 L lM t f l t L t g t t dt
Melnikov function
(28)
The Melnikov function has the infinite number of simple roots This proves the fact of the motion chaotization at the presence of small harmonic perturbations
22 2 2 2
2 1
C B C EB
p t y t q t s k y t E r t y t t r tA A B B C C
0
sin cosN
n p n pn
Q t a n t b n t
22 2 2 2 2
20 0
1 2 1 2 1 2 2 20 1 0 1
sin cos 1
2 2
LI L l l L LQ Q Q t
A A A B C C I I
H H H H H
0 0 1 1
L L
L l L l
l l
L f l L gf f g g
l L l Ll f l L g
H H H H
0 0 00
cos sinN
ns n p n p
n
M t J a n t b n t
(27)
(26)
00 0 2
2
00 1 2 02
4 exp
exp 4
M aa E y t
ky t
Mt aE y a a a
k
23
2 l L I
I8 Numerical modeling Poincareacute sections mod 2 0pt
2 22 2 2 1 1 2 1 3 5
0 0 0 0
15 10 6 5 4[ ] 20 5 [ ] 075 [1 ] 1 5 20 [1]
) 5 004 ) 5 01 ) 10 01 ) 15 02
pA B C A C kg m I kg m s s a a a
a Q b Q c Q d Q
(a) (b)
(c) (d)
II The spider-type systems motion 24
m r K K K
1 2
3 4
5 6
4 2 m r
Ap p
Bq J I q I
Cr r
K K
ed
dt
Kω K M
12 56 34
34 12 56
56 34 12
ex
ey
ez
Ap I C B qr I q r M
Bq I A C pr I r p M
Cr I B A pq I p q M
4 2
4 2 4 2
iji j A A J I
B B J I C C J I
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i ex x
i e i ey y
i e i ez z
I p M M I p M M
I q M M I q M M
I r M M I r M M
(1)
(2)
(3)
(4)
II1 Angular momentum of the system in projections onto axes of the frame Oxyz
II2 The motion equations of the multirotor system
25
1 1
1 1
4 2
4 2 4 2
N Nij
il jl ll l
N N
l ll l
A A J NI
B B J NI C C J NI
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i el l lx l l lx
i e i el l ly l l ly
i e i el l lz l l lz
I p M M I p M M
I q M M I q M M
I r M M I r M M
0
1
2
3
cos 2
cos sin2
cos sin2
cos sin2
2 λ Θ λ
0
1
2
3
0
0
0
0
p q r
p r q
q r p
r q p
λ Θ
(4rsquo)
II3 The Euler parameters
(5)
26II4 The conjugate spinups and captures
Def1 Conjugate rotors are paired rotors located in the same layer on the opposite rays For example rotor 3N and rotor 4N are conjugate rotors (also rotor 12 and rotor 22 etc)
Def2 Conjugate spinup mean a process of spinning up conjugate rotors in opposite directions up to a desired value of relative angular velocity with the help of internal moments from main body Velocities of conjugate rotors will be equal in absolute value and opposite in sign
Def3 Rotor capture is an immediate deceleration of rotor relative angular velocity with the help of internal moment from the main body So rotor capture means an ldquoinstantaneous freezingrdquo of rotor with respect to the main body The capture can be performed with the help of gear meshing friction clutch or other methods
27
(6)
II6 Analytical solutions of motion equations
0e e ex y zM M M
A B C D
12 121
12 122
0
0
0
0
si
si
M if t tM
otherwise
M if t tM
otherwise
12 12 12sS M t I
1 12 2 12S S
1 1 12c c st t t
1 0
12
122
ISp
A IAS
A I
1 0 Conjugate spinup of rotors 1 2
Rotor 1 capture
Rotor 2 capture
2 2 1c c ct t t
1 2
121 2
0 0
c c
c c
t t tp IS
P t t tA I
Two serial captures of conjugate rotors bring to piecewise constant angular velocity of the main body
The main body performed the rotation about Ox axis by finite angle 12 2 1
c c
x
IS t t
A I
28
1 3 5 2 4 6
0 1 2 3
1 0
c c c c c c c cstart finish
c c c cstart start start start
t t t t t t t t
t t t t
0 1
2 3
2 2 2
cos sin2 2
sin sin2 2
c cstart start
c cstart start
c c c cstart finish finish start
t t t tPt t
t t t tQ Rt t
P Q R t t t T t t
1 2 t t t p P q Q r R
Letrsquos assume synchronically captures of coresponded conjugate rotors 1 2 3 4 5 6 and coincidence of the frame Oxyz initial position and the fixed frame OXYZ
Angular velocities between conjugate captures of rotors
Solutions of kinematic equations (5)
cos cos cosT
P Q R
T
e
The main body performed finite rotation about vector e by angle χ
(18)
(20)
(19)
(21)
29II7 Numerical simulation of reorientation process
const 0 1 135 246
i s cj jj j j
i s cj jj j j
jj
M M H t H t t H t t
M M H t H t t H t t
M j j
Two sets of results of numerical simulation
1 4 5(0) (0) (0) 0 (0) 100 1 s ω
ν = 300 Nms
H(t) is Heaviside function
FigA - zero value of angular momentum and different inertia moments of main body
Fig A Fig B
Fig4 - reorientation process at nonzero system angular momentum
30
__________________________________________________________
The main properties of the attitude stabilization and control of SC (and multirotor systems) have been examined
Research into attitude motion of the one-body-SC dual-spin SC and spider-type-SC is very complicated
Nontrivial and chaotic modes are possible in the SC attitude motion
Conclusion
- Slide 1
- Outline
- Part 1 - Introduction to Attitude Dynamics and Control
- Slide 4
- Spin stabilization
- Spin Stabilization Dual-Spin Spacecraft
- Spin Stabilization Dual-Spin Spacecraft (2)
- Spin Stabilization Dual-Spin Spacecraft (3)
- Spin Stabilization Dual-Spin Spacecraft (4)
- Gravity Gradient Stabilization
- Magnetic Stabilization
- Aerodynamic Stabilization
- Actuators
- Actuators (2)
- Actuators (3)
- Main Equations of Angular Motion of Rigid Body (Attitude Motion
- Main Properties of the Free Angular Motion of Rigid Body (Attit
- Main Properties of the Free Angular Motion of Rigid Body (Attit (2)
- Part 2 ndash Research Results
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
-
Aerodynamic Stabilization 7
The Aerodynamic stabilization is a method of SC stabilizing using aerodynamic force in rarefied atmosphere of low earth orbit
SC is positioned along the orbital velocity vector
Aerodynamically Stable CubeSat Design Concept
ldquogo like an arrow helliprdquo
SC with tail unit
Actuators 8Reaction Wheel Assemblies (RWAs)
RWAs are particularly useful when the spacecraft must be rotated by very small amounts such as keeping a telescope pointed at a star
This is accomplished by equipping the spacecraft with an electric motor attached to a flywheel which when rotated increasingly fast causes the spacecraft to spin the other way in a proportional amount by conservation of angular momentum
Actuators 9Control Moment Gyros (CMGs)
A CMG consists of a spinning rotor and one or more motorized gimbals that tilt the rotorrsquos angular momentum As the rotor tilts the changing angular momentum causes a gyroscopic torque that rotates the spacecraft
Microsatellite with four control moment gyroscopes
Actuators 10Thrusters
A thruster is a small propulsive device used by spacecraft for attitude control in the reaction control system or long-duration low-thrust acceleration
Liquefied gases in high-pressure balloons
Main Equations of Angular Motion of Rigid Body(Attitude Motion of SC)
11
Euler dynamical equations
Euler kinematical equations
The study of the angular motion of the SC attitude dynamics is one of the main problems of rigid body systems dynamics in the classical mechanics
And vice versa
Tasks of analysis and synthesis of the rigid bodiesrsquo motion have important applications in the space-flight dynamics
Main Properties of the Free Angular Motion of Rigid Body(Attitude Motion of SC)
12
Louis Poinsot interpreacutetation
Inertia tensor with polhodes
--- notation by CDHall
Main Properties of the Free Angular Motion of Rigid Body(Attitude Motion of SC)
12
If we consider rigid body angular motion on the base of Hamilton dynamics than for rigid body motion we take pendulum phase structure
x=tetta (nutation) and
y = impulse (tetta) ~ d(tetta)dt
Pendulum phase space
Part 2 ndash Research Results
1 The magnetized dual-spin spacecraft attitude motion
2 The regular and chaotic dynamics of dual-spin spacecraft
3 The multi-rotor system and multi-spin spacecraft dynamics
13
14
Letrsquos consider an angular motion (about point O) of spider-type multiple rotor rigid bodies systems and
coaxial bodies systems
Mechanical models of multiple-rotor systems
Coaxial bodies system(dual-spin spacecraft)
Multirotor spiders(gyrostat-spacecrafts)
Number of rotors = N
Number of rotors = 6 Number of rotors = 1
1cos sin
cos
sin cos
sincos sin
cos
p q
p q
r p q
(1)
(2)
15
I1 The angular motion general equations
I The coaxial bodies system motion
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
cos sinP
P Q M Q
The coaxial top
I2 The angular motion equations of the magnetic DSSC and the coaxial Lagrange top
16
The single dipole model of the Earthrsquos magnetic field and the constant magnetic field vector corresponding to the circle equatorial orbit
The magnetic DSSC coordinate frames
17I3 The equations
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
2 2 2
2 1
0
T
x y zOx y z
T
orb orb
M M M
B m B m
oθ
θ
rbM m B
M
1 2
2 2
3 2
cos
cos
cos
OZ Ox
OZ Oy
OZ Oz
i k
j k
k k
2 2
2 1
2
0
Ap C B qr q Q
Bq A C pr p Q
C r B A pq M
orbQ B m
1
22 2 2 2 22
1 2 1 2 1 2
sin cos 1
2 2
T P
LI L l lT
A A A B C C
H H
cos sinP
P Q M Q
(6)
(5)
(4)
(3)
(2)
(1)
18I4 The integrals and solutions
2
2
2
1
2
23
x
y
z
K Ap
K KK Bq
K KK C r
K K
2
2
2
2 3
2
const
cos
z
z
L K C r
I I K
K C rL
K K K
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
2
2 2 22 2
1
2 2Ap Bq C r E C r TC
22 2 2 2 22 2A p B q C r K DT
2 1 2
22 21
2
22 2
Bq A C f q f q
C B C Ff q V E
A A B A A B
H B A B qf q V V
C A C
- AV Doroshin Exact Solutions in Attitude Dynamics of a Magnetic Dual-Spin Spacecraft and a Generalization of the Lagrange Top WSEAS Transactions on Systems Issue 10 Volume 12 (2013)
471-482
(11) (10)
(9)
(8) (7)
19I5 The analytical solution
The polhodes ellipsoid
2
2 2
22 2
2 1
1
1
q t H C A C x t SB A B
p t C B C x t FA A B
EAr t x t S t r t
A C C
2 20 0
2 20 0
sn
sn
i
i
R P c N t t I kx t e
R P c N t t I k
S E
The numerical integration (lines) and analytical (points) results
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075 q0=2 r0=583 [1s] K=50
[kgm2s] Q=100 [kgm2s2]
5
(13)
(12)
20I6 The analytical solution for Euler angles
orbB
K2K + ω timesK = mtimesK
K + ΩtimesK = 0
orbB
K 2Ω ω m
γ + Ωtimes γ = 0
1
2
3 2
t Ap t K
t Bq t K
C r t K
2cos
tg
t C r t K
Ap tt
Bq t
0
0
2 2
0 2 2 2 2
01
( ) ( )
( ) ( )
( )
t
t
t
t
Ap t Bq tt K dt
A p t B q t
t r t dtC
5
10 20 3003 052 08
The numerical integration (lines) and analytical (points) results for the directional cosines
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075
q0=2 r0=583 [1s] K=50 [km2s]
Q=100 [kgm2s2]
(19)
(20)
(18) (17)
(16)
(15)
(14)
21I7 Hamilton form of equations in the Andoyer-Deprit variables
(21)
(25)
(22)
(23)
(24)
1 C r
22
3 23
T T
T
L I Kl
I L I
K k K s K
K k
2
2
2
2 22
2 22
2
sin
cos
x
y
z
K Ap I L l
K Bq I L l
K C r L
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
22 2 2 2 22
1 2 1 2 1 2 2
sin cos 1
2 2
LI L l l LQ
A A A B C C I
H
22
(26)
Hamilton form of equations 2 2 2 1 1A B C A C
Equations (21) have heteroclinic solutions
Perturbations
0 0 L lM t f l t L t g t t dt
Melnikov function
(28)
The Melnikov function has the infinite number of simple roots This proves the fact of the motion chaotization at the presence of small harmonic perturbations
22 2 2 2
2 1
C B C EB
p t y t q t s k y t E r t y t t r tA A B B C C
0
sin cosN
n p n pn
Q t a n t b n t
22 2 2 2 2
20 0
1 2 1 2 1 2 2 20 1 0 1
sin cos 1
2 2
LI L l l L LQ Q Q t
A A A B C C I I
H H H H H
0 0 1 1
L L
L l L l
l l
L f l L gf f g g
l L l Ll f l L g
H H H H
0 0 00
cos sinN
ns n p n p
n
M t J a n t b n t
(27)
(26)
00 0 2
2
00 1 2 02
4 exp
exp 4
M aa E y t
ky t
Mt aE y a a a
k
23
2 l L I
I8 Numerical modeling Poincareacute sections mod 2 0pt
2 22 2 2 1 1 2 1 3 5
0 0 0 0
15 10 6 5 4[ ] 20 5 [ ] 075 [1 ] 1 5 20 [1]
) 5 004 ) 5 01 ) 10 01 ) 15 02
pA B C A C kg m I kg m s s a a a
a Q b Q c Q d Q
(a) (b)
(c) (d)
II The spider-type systems motion 24
m r K K K
1 2
3 4
5 6
4 2 m r
Ap p
Bq J I q I
Cr r
K K
ed
dt
Kω K M
12 56 34
34 12 56
56 34 12
ex
ey
ez
Ap I C B qr I q r M
Bq I A C pr I r p M
Cr I B A pq I p q M
4 2
4 2 4 2
iji j A A J I
B B J I C C J I
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i ex x
i e i ey y
i e i ez z
I p M M I p M M
I q M M I q M M
I r M M I r M M
(1)
(2)
(3)
(4)
II1 Angular momentum of the system in projections onto axes of the frame Oxyz
II2 The motion equations of the multirotor system
25
1 1
1 1
4 2
4 2 4 2
N Nij
il jl ll l
N N
l ll l
A A J NI
B B J NI C C J NI
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i el l lx l l lx
i e i el l ly l l ly
i e i el l lz l l lz
I p M M I p M M
I q M M I q M M
I r M M I r M M
0
1
2
3
cos 2
cos sin2
cos sin2
cos sin2
2 λ Θ λ
0
1
2
3
0
0
0
0
p q r
p r q
q r p
r q p
λ Θ
(4rsquo)
II3 The Euler parameters
(5)
26II4 The conjugate spinups and captures
Def1 Conjugate rotors are paired rotors located in the same layer on the opposite rays For example rotor 3N and rotor 4N are conjugate rotors (also rotor 12 and rotor 22 etc)
Def2 Conjugate spinup mean a process of spinning up conjugate rotors in opposite directions up to a desired value of relative angular velocity with the help of internal moments from main body Velocities of conjugate rotors will be equal in absolute value and opposite in sign
Def3 Rotor capture is an immediate deceleration of rotor relative angular velocity with the help of internal moment from the main body So rotor capture means an ldquoinstantaneous freezingrdquo of rotor with respect to the main body The capture can be performed with the help of gear meshing friction clutch or other methods
27
(6)
II6 Analytical solutions of motion equations
0e e ex y zM M M
A B C D
12 121
12 122
0
0
0
0
si
si
M if t tM
otherwise
M if t tM
otherwise
12 12 12sS M t I
1 12 2 12S S
1 1 12c c st t t
1 0
12
122
ISp
A IAS
A I
1 0 Conjugate spinup of rotors 1 2
Rotor 1 capture
Rotor 2 capture
2 2 1c c ct t t
1 2
121 2
0 0
c c
c c
t t tp IS
P t t tA I
Two serial captures of conjugate rotors bring to piecewise constant angular velocity of the main body
The main body performed the rotation about Ox axis by finite angle 12 2 1
c c
x
IS t t
A I
28
1 3 5 2 4 6
0 1 2 3
1 0
c c c c c c c cstart finish
c c c cstart start start start
t t t t t t t t
t t t t
0 1
2 3
2 2 2
cos sin2 2
sin sin2 2
c cstart start
c cstart start
c c c cstart finish finish start
t t t tPt t
t t t tQ Rt t
P Q R t t t T t t
1 2 t t t p P q Q r R
Letrsquos assume synchronically captures of coresponded conjugate rotors 1 2 3 4 5 6 and coincidence of the frame Oxyz initial position and the fixed frame OXYZ
Angular velocities between conjugate captures of rotors
Solutions of kinematic equations (5)
cos cos cosT
P Q R
T
e
The main body performed finite rotation about vector e by angle χ
(18)
(20)
(19)
(21)
29II7 Numerical simulation of reorientation process
const 0 1 135 246
i s cj jj j j
i s cj jj j j
jj
M M H t H t t H t t
M M H t H t t H t t
M j j
Two sets of results of numerical simulation
1 4 5(0) (0) (0) 0 (0) 100 1 s ω
ν = 300 Nms
H(t) is Heaviside function
FigA - zero value of angular momentum and different inertia moments of main body
Fig A Fig B
Fig4 - reorientation process at nonzero system angular momentum
30
__________________________________________________________
The main properties of the attitude stabilization and control of SC (and multirotor systems) have been examined
Research into attitude motion of the one-body-SC dual-spin SC and spider-type-SC is very complicated
Nontrivial and chaotic modes are possible in the SC attitude motion
Conclusion
- Slide 1
- Outline
- Part 1 - Introduction to Attitude Dynamics and Control
- Slide 4
- Spin stabilization
- Spin Stabilization Dual-Spin Spacecraft
- Spin Stabilization Dual-Spin Spacecraft (2)
- Spin Stabilization Dual-Spin Spacecraft (3)
- Spin Stabilization Dual-Spin Spacecraft (4)
- Gravity Gradient Stabilization
- Magnetic Stabilization
- Aerodynamic Stabilization
- Actuators
- Actuators (2)
- Actuators (3)
- Main Equations of Angular Motion of Rigid Body (Attitude Motion
- Main Properties of the Free Angular Motion of Rigid Body (Attit
- Main Properties of the Free Angular Motion of Rigid Body (Attit (2)
- Part 2 ndash Research Results
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
-
Actuators 8Reaction Wheel Assemblies (RWAs)
RWAs are particularly useful when the spacecraft must be rotated by very small amounts such as keeping a telescope pointed at a star
This is accomplished by equipping the spacecraft with an electric motor attached to a flywheel which when rotated increasingly fast causes the spacecraft to spin the other way in a proportional amount by conservation of angular momentum
Actuators 9Control Moment Gyros (CMGs)
A CMG consists of a spinning rotor and one or more motorized gimbals that tilt the rotorrsquos angular momentum As the rotor tilts the changing angular momentum causes a gyroscopic torque that rotates the spacecraft
Microsatellite with four control moment gyroscopes
Actuators 10Thrusters
A thruster is a small propulsive device used by spacecraft for attitude control in the reaction control system or long-duration low-thrust acceleration
Liquefied gases in high-pressure balloons
Main Equations of Angular Motion of Rigid Body(Attitude Motion of SC)
11
Euler dynamical equations
Euler kinematical equations
The study of the angular motion of the SC attitude dynamics is one of the main problems of rigid body systems dynamics in the classical mechanics
And vice versa
Tasks of analysis and synthesis of the rigid bodiesrsquo motion have important applications in the space-flight dynamics
Main Properties of the Free Angular Motion of Rigid Body(Attitude Motion of SC)
12
Louis Poinsot interpreacutetation
Inertia tensor with polhodes
--- notation by CDHall
Main Properties of the Free Angular Motion of Rigid Body(Attitude Motion of SC)
12
If we consider rigid body angular motion on the base of Hamilton dynamics than for rigid body motion we take pendulum phase structure
x=tetta (nutation) and
y = impulse (tetta) ~ d(tetta)dt
Pendulum phase space
Part 2 ndash Research Results
1 The magnetized dual-spin spacecraft attitude motion
2 The regular and chaotic dynamics of dual-spin spacecraft
3 The multi-rotor system and multi-spin spacecraft dynamics
13
14
Letrsquos consider an angular motion (about point O) of spider-type multiple rotor rigid bodies systems and
coaxial bodies systems
Mechanical models of multiple-rotor systems
Coaxial bodies system(dual-spin spacecraft)
Multirotor spiders(gyrostat-spacecrafts)
Number of rotors = N
Number of rotors = 6 Number of rotors = 1
1cos sin
cos
sin cos
sincos sin
cos
p q
p q
r p q
(1)
(2)
15
I1 The angular motion general equations
I The coaxial bodies system motion
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
cos sinP
P Q M Q
The coaxial top
I2 The angular motion equations of the magnetic DSSC and the coaxial Lagrange top
16
The single dipole model of the Earthrsquos magnetic field and the constant magnetic field vector corresponding to the circle equatorial orbit
The magnetic DSSC coordinate frames
17I3 The equations
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
2 2 2
2 1
0
T
x y zOx y z
T
orb orb
M M M
B m B m
oθ
θ
rbM m B
M
1 2
2 2
3 2
cos
cos
cos
OZ Ox
OZ Oy
OZ Oz
i k
j k
k k
2 2
2 1
2
0
Ap C B qr q Q
Bq A C pr p Q
C r B A pq M
orbQ B m
1
22 2 2 2 22
1 2 1 2 1 2
sin cos 1
2 2
T P
LI L l lT
A A A B C C
H H
cos sinP
P Q M Q
(6)
(5)
(4)
(3)
(2)
(1)
18I4 The integrals and solutions
2
2
2
1
2
23
x
y
z
K Ap
K KK Bq
K KK C r
K K
2
2
2
2 3
2
const
cos
z
z
L K C r
I I K
K C rL
K K K
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
2
2 2 22 2
1
2 2Ap Bq C r E C r TC
22 2 2 2 22 2A p B q C r K DT
2 1 2
22 21
2
22 2
Bq A C f q f q
C B C Ff q V E
A A B A A B
H B A B qf q V V
C A C
- AV Doroshin Exact Solutions in Attitude Dynamics of a Magnetic Dual-Spin Spacecraft and a Generalization of the Lagrange Top WSEAS Transactions on Systems Issue 10 Volume 12 (2013)
471-482
(11) (10)
(9)
(8) (7)
19I5 The analytical solution
The polhodes ellipsoid
2
2 2
22 2
2 1
1
1
q t H C A C x t SB A B
p t C B C x t FA A B
EAr t x t S t r t
A C C
2 20 0
2 20 0
sn
sn
i
i
R P c N t t I kx t e
R P c N t t I k
S E
The numerical integration (lines) and analytical (points) results
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075 q0=2 r0=583 [1s] K=50
[kgm2s] Q=100 [kgm2s2]
5
(13)
(12)
20I6 The analytical solution for Euler angles
orbB
K2K + ω timesK = mtimesK
K + ΩtimesK = 0
orbB
K 2Ω ω m
γ + Ωtimes γ = 0
1
2
3 2
t Ap t K
t Bq t K
C r t K
2cos
tg
t C r t K
Ap tt
Bq t
0
0
2 2
0 2 2 2 2
01
( ) ( )
( ) ( )
( )
t
t
t
t
Ap t Bq tt K dt
A p t B q t
t r t dtC
5
10 20 3003 052 08
The numerical integration (lines) and analytical (points) results for the directional cosines
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075
q0=2 r0=583 [1s] K=50 [km2s]
Q=100 [kgm2s2]
(19)
(20)
(18) (17)
(16)
(15)
(14)
21I7 Hamilton form of equations in the Andoyer-Deprit variables
(21)
(25)
(22)
(23)
(24)
1 C r
22
3 23
T T
T
L I Kl
I L I
K k K s K
K k
2
2
2
2 22
2 22
2
sin
cos
x
y
z
K Ap I L l
K Bq I L l
K C r L
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
22 2 2 2 22
1 2 1 2 1 2 2
sin cos 1
2 2
LI L l l LQ
A A A B C C I
H
22
(26)
Hamilton form of equations 2 2 2 1 1A B C A C
Equations (21) have heteroclinic solutions
Perturbations
0 0 L lM t f l t L t g t t dt
Melnikov function
(28)
The Melnikov function has the infinite number of simple roots This proves the fact of the motion chaotization at the presence of small harmonic perturbations
22 2 2 2
2 1
C B C EB
p t y t q t s k y t E r t y t t r tA A B B C C
0
sin cosN
n p n pn
Q t a n t b n t
22 2 2 2 2
20 0
1 2 1 2 1 2 2 20 1 0 1
sin cos 1
2 2
LI L l l L LQ Q Q t
A A A B C C I I
H H H H H
0 0 1 1
L L
L l L l
l l
L f l L gf f g g
l L l Ll f l L g
H H H H
0 0 00
cos sinN
ns n p n p
n
M t J a n t b n t
(27)
(26)
00 0 2
2
00 1 2 02
4 exp
exp 4
M aa E y t
ky t
Mt aE y a a a
k
23
2 l L I
I8 Numerical modeling Poincareacute sections mod 2 0pt
2 22 2 2 1 1 2 1 3 5
0 0 0 0
15 10 6 5 4[ ] 20 5 [ ] 075 [1 ] 1 5 20 [1]
) 5 004 ) 5 01 ) 10 01 ) 15 02
pA B C A C kg m I kg m s s a a a
a Q b Q c Q d Q
(a) (b)
(c) (d)
II The spider-type systems motion 24
m r K K K
1 2
3 4
5 6
4 2 m r
Ap p
Bq J I q I
Cr r
K K
ed
dt
Kω K M
12 56 34
34 12 56
56 34 12
ex
ey
ez
Ap I C B qr I q r M
Bq I A C pr I r p M
Cr I B A pq I p q M
4 2
4 2 4 2
iji j A A J I
B B J I C C J I
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i ex x
i e i ey y
i e i ez z
I p M M I p M M
I q M M I q M M
I r M M I r M M
(1)
(2)
(3)
(4)
II1 Angular momentum of the system in projections onto axes of the frame Oxyz
II2 The motion equations of the multirotor system
25
1 1
1 1
4 2
4 2 4 2
N Nij
il jl ll l
N N
l ll l
A A J NI
B B J NI C C J NI
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i el l lx l l lx
i e i el l ly l l ly
i e i el l lz l l lz
I p M M I p M M
I q M M I q M M
I r M M I r M M
0
1
2
3
cos 2
cos sin2
cos sin2
cos sin2
2 λ Θ λ
0
1
2
3
0
0
0
0
p q r
p r q
q r p
r q p
λ Θ
(4rsquo)
II3 The Euler parameters
(5)
26II4 The conjugate spinups and captures
Def1 Conjugate rotors are paired rotors located in the same layer on the opposite rays For example rotor 3N and rotor 4N are conjugate rotors (also rotor 12 and rotor 22 etc)
Def2 Conjugate spinup mean a process of spinning up conjugate rotors in opposite directions up to a desired value of relative angular velocity with the help of internal moments from main body Velocities of conjugate rotors will be equal in absolute value and opposite in sign
Def3 Rotor capture is an immediate deceleration of rotor relative angular velocity with the help of internal moment from the main body So rotor capture means an ldquoinstantaneous freezingrdquo of rotor with respect to the main body The capture can be performed with the help of gear meshing friction clutch or other methods
27
(6)
II6 Analytical solutions of motion equations
0e e ex y zM M M
A B C D
12 121
12 122
0
0
0
0
si
si
M if t tM
otherwise
M if t tM
otherwise
12 12 12sS M t I
1 12 2 12S S
1 1 12c c st t t
1 0
12
122
ISp
A IAS
A I
1 0 Conjugate spinup of rotors 1 2
Rotor 1 capture
Rotor 2 capture
2 2 1c c ct t t
1 2
121 2
0 0
c c
c c
t t tp IS
P t t tA I
Two serial captures of conjugate rotors bring to piecewise constant angular velocity of the main body
The main body performed the rotation about Ox axis by finite angle 12 2 1
c c
x
IS t t
A I
28
1 3 5 2 4 6
0 1 2 3
1 0
c c c c c c c cstart finish
c c c cstart start start start
t t t t t t t t
t t t t
0 1
2 3
2 2 2
cos sin2 2
sin sin2 2
c cstart start
c cstart start
c c c cstart finish finish start
t t t tPt t
t t t tQ Rt t
P Q R t t t T t t
1 2 t t t p P q Q r R
Letrsquos assume synchronically captures of coresponded conjugate rotors 1 2 3 4 5 6 and coincidence of the frame Oxyz initial position and the fixed frame OXYZ
Angular velocities between conjugate captures of rotors
Solutions of kinematic equations (5)
cos cos cosT
P Q R
T
e
The main body performed finite rotation about vector e by angle χ
(18)
(20)
(19)
(21)
29II7 Numerical simulation of reorientation process
const 0 1 135 246
i s cj jj j j
i s cj jj j j
jj
M M H t H t t H t t
M M H t H t t H t t
M j j
Two sets of results of numerical simulation
1 4 5(0) (0) (0) 0 (0) 100 1 s ω
ν = 300 Nms
H(t) is Heaviside function
FigA - zero value of angular momentum and different inertia moments of main body
Fig A Fig B
Fig4 - reorientation process at nonzero system angular momentum
30
__________________________________________________________
The main properties of the attitude stabilization and control of SC (and multirotor systems) have been examined
Research into attitude motion of the one-body-SC dual-spin SC and spider-type-SC is very complicated
Nontrivial and chaotic modes are possible in the SC attitude motion
Conclusion
- Slide 1
- Outline
- Part 1 - Introduction to Attitude Dynamics and Control
- Slide 4
- Spin stabilization
- Spin Stabilization Dual-Spin Spacecraft
- Spin Stabilization Dual-Spin Spacecraft (2)
- Spin Stabilization Dual-Spin Spacecraft (3)
- Spin Stabilization Dual-Spin Spacecraft (4)
- Gravity Gradient Stabilization
- Magnetic Stabilization
- Aerodynamic Stabilization
- Actuators
- Actuators (2)
- Actuators (3)
- Main Equations of Angular Motion of Rigid Body (Attitude Motion
- Main Properties of the Free Angular Motion of Rigid Body (Attit
- Main Properties of the Free Angular Motion of Rigid Body (Attit (2)
- Part 2 ndash Research Results
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
-
Actuators 9Control Moment Gyros (CMGs)
A CMG consists of a spinning rotor and one or more motorized gimbals that tilt the rotorrsquos angular momentum As the rotor tilts the changing angular momentum causes a gyroscopic torque that rotates the spacecraft
Microsatellite with four control moment gyroscopes
Actuators 10Thrusters
A thruster is a small propulsive device used by spacecraft for attitude control in the reaction control system or long-duration low-thrust acceleration
Liquefied gases in high-pressure balloons
Main Equations of Angular Motion of Rigid Body(Attitude Motion of SC)
11
Euler dynamical equations
Euler kinematical equations
The study of the angular motion of the SC attitude dynamics is one of the main problems of rigid body systems dynamics in the classical mechanics
And vice versa
Tasks of analysis and synthesis of the rigid bodiesrsquo motion have important applications in the space-flight dynamics
Main Properties of the Free Angular Motion of Rigid Body(Attitude Motion of SC)
12
Louis Poinsot interpreacutetation
Inertia tensor with polhodes
--- notation by CDHall
Main Properties of the Free Angular Motion of Rigid Body(Attitude Motion of SC)
12
If we consider rigid body angular motion on the base of Hamilton dynamics than for rigid body motion we take pendulum phase structure
x=tetta (nutation) and
y = impulse (tetta) ~ d(tetta)dt
Pendulum phase space
Part 2 ndash Research Results
1 The magnetized dual-spin spacecraft attitude motion
2 The regular and chaotic dynamics of dual-spin spacecraft
3 The multi-rotor system and multi-spin spacecraft dynamics
13
14
Letrsquos consider an angular motion (about point O) of spider-type multiple rotor rigid bodies systems and
coaxial bodies systems
Mechanical models of multiple-rotor systems
Coaxial bodies system(dual-spin spacecraft)
Multirotor spiders(gyrostat-spacecrafts)
Number of rotors = N
Number of rotors = 6 Number of rotors = 1
1cos sin
cos
sin cos
sincos sin
cos
p q
p q
r p q
(1)
(2)
15
I1 The angular motion general equations
I The coaxial bodies system motion
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
cos sinP
P Q M Q
The coaxial top
I2 The angular motion equations of the magnetic DSSC and the coaxial Lagrange top
16
The single dipole model of the Earthrsquos magnetic field and the constant magnetic field vector corresponding to the circle equatorial orbit
The magnetic DSSC coordinate frames
17I3 The equations
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
2 2 2
2 1
0
T
x y zOx y z
T
orb orb
M M M
B m B m
oθ
θ
rbM m B
M
1 2
2 2
3 2
cos
cos
cos
OZ Ox
OZ Oy
OZ Oz
i k
j k
k k
2 2
2 1
2
0
Ap C B qr q Q
Bq A C pr p Q
C r B A pq M
orbQ B m
1
22 2 2 2 22
1 2 1 2 1 2
sin cos 1
2 2
T P
LI L l lT
A A A B C C
H H
cos sinP
P Q M Q
(6)
(5)
(4)
(3)
(2)
(1)
18I4 The integrals and solutions
2
2
2
1
2
23
x
y
z
K Ap
K KK Bq
K KK C r
K K
2
2
2
2 3
2
const
cos
z
z
L K C r
I I K
K C rL
K K K
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
2
2 2 22 2
1
2 2Ap Bq C r E C r TC
22 2 2 2 22 2A p B q C r K DT
2 1 2
22 21
2
22 2
Bq A C f q f q
C B C Ff q V E
A A B A A B
H B A B qf q V V
C A C
- AV Doroshin Exact Solutions in Attitude Dynamics of a Magnetic Dual-Spin Spacecraft and a Generalization of the Lagrange Top WSEAS Transactions on Systems Issue 10 Volume 12 (2013)
471-482
(11) (10)
(9)
(8) (7)
19I5 The analytical solution
The polhodes ellipsoid
2
2 2
22 2
2 1
1
1
q t H C A C x t SB A B
p t C B C x t FA A B
EAr t x t S t r t
A C C
2 20 0
2 20 0
sn
sn
i
i
R P c N t t I kx t e
R P c N t t I k
S E
The numerical integration (lines) and analytical (points) results
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075 q0=2 r0=583 [1s] K=50
[kgm2s] Q=100 [kgm2s2]
5
(13)
(12)
20I6 The analytical solution for Euler angles
orbB
K2K + ω timesK = mtimesK
K + ΩtimesK = 0
orbB
K 2Ω ω m
γ + Ωtimes γ = 0
1
2
3 2
t Ap t K
t Bq t K
C r t K
2cos
tg
t C r t K
Ap tt
Bq t
0
0
2 2
0 2 2 2 2
01
( ) ( )
( ) ( )
( )
t
t
t
t
Ap t Bq tt K dt
A p t B q t
t r t dtC
5
10 20 3003 052 08
The numerical integration (lines) and analytical (points) results for the directional cosines
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075
q0=2 r0=583 [1s] K=50 [km2s]
Q=100 [kgm2s2]
(19)
(20)
(18) (17)
(16)
(15)
(14)
21I7 Hamilton form of equations in the Andoyer-Deprit variables
(21)
(25)
(22)
(23)
(24)
1 C r
22
3 23
T T
T
L I Kl
I L I
K k K s K
K k
2
2
2
2 22
2 22
2
sin
cos
x
y
z
K Ap I L l
K Bq I L l
K C r L
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
22 2 2 2 22
1 2 1 2 1 2 2
sin cos 1
2 2
LI L l l LQ
A A A B C C I
H
22
(26)
Hamilton form of equations 2 2 2 1 1A B C A C
Equations (21) have heteroclinic solutions
Perturbations
0 0 L lM t f l t L t g t t dt
Melnikov function
(28)
The Melnikov function has the infinite number of simple roots This proves the fact of the motion chaotization at the presence of small harmonic perturbations
22 2 2 2
2 1
C B C EB
p t y t q t s k y t E r t y t t r tA A B B C C
0
sin cosN
n p n pn
Q t a n t b n t
22 2 2 2 2
20 0
1 2 1 2 1 2 2 20 1 0 1
sin cos 1
2 2
LI L l l L LQ Q Q t
A A A B C C I I
H H H H H
0 0 1 1
L L
L l L l
l l
L f l L gf f g g
l L l Ll f l L g
H H H H
0 0 00
cos sinN
ns n p n p
n
M t J a n t b n t
(27)
(26)
00 0 2
2
00 1 2 02
4 exp
exp 4
M aa E y t
ky t
Mt aE y a a a
k
23
2 l L I
I8 Numerical modeling Poincareacute sections mod 2 0pt
2 22 2 2 1 1 2 1 3 5
0 0 0 0
15 10 6 5 4[ ] 20 5 [ ] 075 [1 ] 1 5 20 [1]
) 5 004 ) 5 01 ) 10 01 ) 15 02
pA B C A C kg m I kg m s s a a a
a Q b Q c Q d Q
(a) (b)
(c) (d)
II The spider-type systems motion 24
m r K K K
1 2
3 4
5 6
4 2 m r
Ap p
Bq J I q I
Cr r
K K
ed
dt
Kω K M
12 56 34
34 12 56
56 34 12
ex
ey
ez
Ap I C B qr I q r M
Bq I A C pr I r p M
Cr I B A pq I p q M
4 2
4 2 4 2
iji j A A J I
B B J I C C J I
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i ex x
i e i ey y
i e i ez z
I p M M I p M M
I q M M I q M M
I r M M I r M M
(1)
(2)
(3)
(4)
II1 Angular momentum of the system in projections onto axes of the frame Oxyz
II2 The motion equations of the multirotor system
25
1 1
1 1
4 2
4 2 4 2
N Nij
il jl ll l
N N
l ll l
A A J NI
B B J NI C C J NI
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i el l lx l l lx
i e i el l ly l l ly
i e i el l lz l l lz
I p M M I p M M
I q M M I q M M
I r M M I r M M
0
1
2
3
cos 2
cos sin2
cos sin2
cos sin2
2 λ Θ λ
0
1
2
3
0
0
0
0
p q r
p r q
q r p
r q p
λ Θ
(4rsquo)
II3 The Euler parameters
(5)
26II4 The conjugate spinups and captures
Def1 Conjugate rotors are paired rotors located in the same layer on the opposite rays For example rotor 3N and rotor 4N are conjugate rotors (also rotor 12 and rotor 22 etc)
Def2 Conjugate spinup mean a process of spinning up conjugate rotors in opposite directions up to a desired value of relative angular velocity with the help of internal moments from main body Velocities of conjugate rotors will be equal in absolute value and opposite in sign
Def3 Rotor capture is an immediate deceleration of rotor relative angular velocity with the help of internal moment from the main body So rotor capture means an ldquoinstantaneous freezingrdquo of rotor with respect to the main body The capture can be performed with the help of gear meshing friction clutch or other methods
27
(6)
II6 Analytical solutions of motion equations
0e e ex y zM M M
A B C D
12 121
12 122
0
0
0
0
si
si
M if t tM
otherwise
M if t tM
otherwise
12 12 12sS M t I
1 12 2 12S S
1 1 12c c st t t
1 0
12
122
ISp
A IAS
A I
1 0 Conjugate spinup of rotors 1 2
Rotor 1 capture
Rotor 2 capture
2 2 1c c ct t t
1 2
121 2
0 0
c c
c c
t t tp IS
P t t tA I
Two serial captures of conjugate rotors bring to piecewise constant angular velocity of the main body
The main body performed the rotation about Ox axis by finite angle 12 2 1
c c
x
IS t t
A I
28
1 3 5 2 4 6
0 1 2 3
1 0
c c c c c c c cstart finish
c c c cstart start start start
t t t t t t t t
t t t t
0 1
2 3
2 2 2
cos sin2 2
sin sin2 2
c cstart start
c cstart start
c c c cstart finish finish start
t t t tPt t
t t t tQ Rt t
P Q R t t t T t t
1 2 t t t p P q Q r R
Letrsquos assume synchronically captures of coresponded conjugate rotors 1 2 3 4 5 6 and coincidence of the frame Oxyz initial position and the fixed frame OXYZ
Angular velocities between conjugate captures of rotors
Solutions of kinematic equations (5)
cos cos cosT
P Q R
T
e
The main body performed finite rotation about vector e by angle χ
(18)
(20)
(19)
(21)
29II7 Numerical simulation of reorientation process
const 0 1 135 246
i s cj jj j j
i s cj jj j j
jj
M M H t H t t H t t
M M H t H t t H t t
M j j
Two sets of results of numerical simulation
1 4 5(0) (0) (0) 0 (0) 100 1 s ω
ν = 300 Nms
H(t) is Heaviside function
FigA - zero value of angular momentum and different inertia moments of main body
Fig A Fig B
Fig4 - reorientation process at nonzero system angular momentum
30
__________________________________________________________
The main properties of the attitude stabilization and control of SC (and multirotor systems) have been examined
Research into attitude motion of the one-body-SC dual-spin SC and spider-type-SC is very complicated
Nontrivial and chaotic modes are possible in the SC attitude motion
Conclusion
- Slide 1
- Outline
- Part 1 - Introduction to Attitude Dynamics and Control
- Slide 4
- Spin stabilization
- Spin Stabilization Dual-Spin Spacecraft
- Spin Stabilization Dual-Spin Spacecraft (2)
- Spin Stabilization Dual-Spin Spacecraft (3)
- Spin Stabilization Dual-Spin Spacecraft (4)
- Gravity Gradient Stabilization
- Magnetic Stabilization
- Aerodynamic Stabilization
- Actuators
- Actuators (2)
- Actuators (3)
- Main Equations of Angular Motion of Rigid Body (Attitude Motion
- Main Properties of the Free Angular Motion of Rigid Body (Attit
- Main Properties of the Free Angular Motion of Rigid Body (Attit (2)
- Part 2 ndash Research Results
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
-
Actuators 10Thrusters
A thruster is a small propulsive device used by spacecraft for attitude control in the reaction control system or long-duration low-thrust acceleration
Liquefied gases in high-pressure balloons
Main Equations of Angular Motion of Rigid Body(Attitude Motion of SC)
11
Euler dynamical equations
Euler kinematical equations
The study of the angular motion of the SC attitude dynamics is one of the main problems of rigid body systems dynamics in the classical mechanics
And vice versa
Tasks of analysis and synthesis of the rigid bodiesrsquo motion have important applications in the space-flight dynamics
Main Properties of the Free Angular Motion of Rigid Body(Attitude Motion of SC)
12
Louis Poinsot interpreacutetation
Inertia tensor with polhodes
--- notation by CDHall
Main Properties of the Free Angular Motion of Rigid Body(Attitude Motion of SC)
12
If we consider rigid body angular motion on the base of Hamilton dynamics than for rigid body motion we take pendulum phase structure
x=tetta (nutation) and
y = impulse (tetta) ~ d(tetta)dt
Pendulum phase space
Part 2 ndash Research Results
1 The magnetized dual-spin spacecraft attitude motion
2 The regular and chaotic dynamics of dual-spin spacecraft
3 The multi-rotor system and multi-spin spacecraft dynamics
13
14
Letrsquos consider an angular motion (about point O) of spider-type multiple rotor rigid bodies systems and
coaxial bodies systems
Mechanical models of multiple-rotor systems
Coaxial bodies system(dual-spin spacecraft)
Multirotor spiders(gyrostat-spacecrafts)
Number of rotors = N
Number of rotors = 6 Number of rotors = 1
1cos sin
cos
sin cos
sincos sin
cos
p q
p q
r p q
(1)
(2)
15
I1 The angular motion general equations
I The coaxial bodies system motion
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
cos sinP
P Q M Q
The coaxial top
I2 The angular motion equations of the magnetic DSSC and the coaxial Lagrange top
16
The single dipole model of the Earthrsquos magnetic field and the constant magnetic field vector corresponding to the circle equatorial orbit
The magnetic DSSC coordinate frames
17I3 The equations
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
2 2 2
2 1
0
T
x y zOx y z
T
orb orb
M M M
B m B m
oθ
θ
rbM m B
M
1 2
2 2
3 2
cos
cos
cos
OZ Ox
OZ Oy
OZ Oz
i k
j k
k k
2 2
2 1
2
0
Ap C B qr q Q
Bq A C pr p Q
C r B A pq M
orbQ B m
1
22 2 2 2 22
1 2 1 2 1 2
sin cos 1
2 2
T P
LI L l lT
A A A B C C
H H
cos sinP
P Q M Q
(6)
(5)
(4)
(3)
(2)
(1)
18I4 The integrals and solutions
2
2
2
1
2
23
x
y
z
K Ap
K KK Bq
K KK C r
K K
2
2
2
2 3
2
const
cos
z
z
L K C r
I I K
K C rL
K K K
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
2
2 2 22 2
1
2 2Ap Bq C r E C r TC
22 2 2 2 22 2A p B q C r K DT
2 1 2
22 21
2
22 2
Bq A C f q f q
C B C Ff q V E
A A B A A B
H B A B qf q V V
C A C
- AV Doroshin Exact Solutions in Attitude Dynamics of a Magnetic Dual-Spin Spacecraft and a Generalization of the Lagrange Top WSEAS Transactions on Systems Issue 10 Volume 12 (2013)
471-482
(11) (10)
(9)
(8) (7)
19I5 The analytical solution
The polhodes ellipsoid
2
2 2
22 2
2 1
1
1
q t H C A C x t SB A B
p t C B C x t FA A B
EAr t x t S t r t
A C C
2 20 0
2 20 0
sn
sn
i
i
R P c N t t I kx t e
R P c N t t I k
S E
The numerical integration (lines) and analytical (points) results
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075 q0=2 r0=583 [1s] K=50
[kgm2s] Q=100 [kgm2s2]
5
(13)
(12)
20I6 The analytical solution for Euler angles
orbB
K2K + ω timesK = mtimesK
K + ΩtimesK = 0
orbB
K 2Ω ω m
γ + Ωtimes γ = 0
1
2
3 2
t Ap t K
t Bq t K
C r t K
2cos
tg
t C r t K
Ap tt
Bq t
0
0
2 2
0 2 2 2 2
01
( ) ( )
( ) ( )
( )
t
t
t
t
Ap t Bq tt K dt
A p t B q t
t r t dtC
5
10 20 3003 052 08
The numerical integration (lines) and analytical (points) results for the directional cosines
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075
q0=2 r0=583 [1s] K=50 [km2s]
Q=100 [kgm2s2]
(19)
(20)
(18) (17)
(16)
(15)
(14)
21I7 Hamilton form of equations in the Andoyer-Deprit variables
(21)
(25)
(22)
(23)
(24)
1 C r
22
3 23
T T
T
L I Kl
I L I
K k K s K
K k
2
2
2
2 22
2 22
2
sin
cos
x
y
z
K Ap I L l
K Bq I L l
K C r L
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
22 2 2 2 22
1 2 1 2 1 2 2
sin cos 1
2 2
LI L l l LQ
A A A B C C I
H
22
(26)
Hamilton form of equations 2 2 2 1 1A B C A C
Equations (21) have heteroclinic solutions
Perturbations
0 0 L lM t f l t L t g t t dt
Melnikov function
(28)
The Melnikov function has the infinite number of simple roots This proves the fact of the motion chaotization at the presence of small harmonic perturbations
22 2 2 2
2 1
C B C EB
p t y t q t s k y t E r t y t t r tA A B B C C
0
sin cosN
n p n pn
Q t a n t b n t
22 2 2 2 2
20 0
1 2 1 2 1 2 2 20 1 0 1
sin cos 1
2 2
LI L l l L LQ Q Q t
A A A B C C I I
H H H H H
0 0 1 1
L L
L l L l
l l
L f l L gf f g g
l L l Ll f l L g
H H H H
0 0 00
cos sinN
ns n p n p
n
M t J a n t b n t
(27)
(26)
00 0 2
2
00 1 2 02
4 exp
exp 4
M aa E y t
ky t
Mt aE y a a a
k
23
2 l L I
I8 Numerical modeling Poincareacute sections mod 2 0pt
2 22 2 2 1 1 2 1 3 5
0 0 0 0
15 10 6 5 4[ ] 20 5 [ ] 075 [1 ] 1 5 20 [1]
) 5 004 ) 5 01 ) 10 01 ) 15 02
pA B C A C kg m I kg m s s a a a
a Q b Q c Q d Q
(a) (b)
(c) (d)
II The spider-type systems motion 24
m r K K K
1 2
3 4
5 6
4 2 m r
Ap p
Bq J I q I
Cr r
K K
ed
dt
Kω K M
12 56 34
34 12 56
56 34 12
ex
ey
ez
Ap I C B qr I q r M
Bq I A C pr I r p M
Cr I B A pq I p q M
4 2
4 2 4 2
iji j A A J I
B B J I C C J I
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i ex x
i e i ey y
i e i ez z
I p M M I p M M
I q M M I q M M
I r M M I r M M
(1)
(2)
(3)
(4)
II1 Angular momentum of the system in projections onto axes of the frame Oxyz
II2 The motion equations of the multirotor system
25
1 1
1 1
4 2
4 2 4 2
N Nij
il jl ll l
N N
l ll l
A A J NI
B B J NI C C J NI
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i el l lx l l lx
i e i el l ly l l ly
i e i el l lz l l lz
I p M M I p M M
I q M M I q M M
I r M M I r M M
0
1
2
3
cos 2
cos sin2
cos sin2
cos sin2
2 λ Θ λ
0
1
2
3
0
0
0
0
p q r
p r q
q r p
r q p
λ Θ
(4rsquo)
II3 The Euler parameters
(5)
26II4 The conjugate spinups and captures
Def1 Conjugate rotors are paired rotors located in the same layer on the opposite rays For example rotor 3N and rotor 4N are conjugate rotors (also rotor 12 and rotor 22 etc)
Def2 Conjugate spinup mean a process of spinning up conjugate rotors in opposite directions up to a desired value of relative angular velocity with the help of internal moments from main body Velocities of conjugate rotors will be equal in absolute value and opposite in sign
Def3 Rotor capture is an immediate deceleration of rotor relative angular velocity with the help of internal moment from the main body So rotor capture means an ldquoinstantaneous freezingrdquo of rotor with respect to the main body The capture can be performed with the help of gear meshing friction clutch or other methods
27
(6)
II6 Analytical solutions of motion equations
0e e ex y zM M M
A B C D
12 121
12 122
0
0
0
0
si
si
M if t tM
otherwise
M if t tM
otherwise
12 12 12sS M t I
1 12 2 12S S
1 1 12c c st t t
1 0
12
122
ISp
A IAS
A I
1 0 Conjugate spinup of rotors 1 2
Rotor 1 capture
Rotor 2 capture
2 2 1c c ct t t
1 2
121 2
0 0
c c
c c
t t tp IS
P t t tA I
Two serial captures of conjugate rotors bring to piecewise constant angular velocity of the main body
The main body performed the rotation about Ox axis by finite angle 12 2 1
c c
x
IS t t
A I
28
1 3 5 2 4 6
0 1 2 3
1 0
c c c c c c c cstart finish
c c c cstart start start start
t t t t t t t t
t t t t
0 1
2 3
2 2 2
cos sin2 2
sin sin2 2
c cstart start
c cstart start
c c c cstart finish finish start
t t t tPt t
t t t tQ Rt t
P Q R t t t T t t
1 2 t t t p P q Q r R
Letrsquos assume synchronically captures of coresponded conjugate rotors 1 2 3 4 5 6 and coincidence of the frame Oxyz initial position and the fixed frame OXYZ
Angular velocities between conjugate captures of rotors
Solutions of kinematic equations (5)
cos cos cosT
P Q R
T
e
The main body performed finite rotation about vector e by angle χ
(18)
(20)
(19)
(21)
29II7 Numerical simulation of reorientation process
const 0 1 135 246
i s cj jj j j
i s cj jj j j
jj
M M H t H t t H t t
M M H t H t t H t t
M j j
Two sets of results of numerical simulation
1 4 5(0) (0) (0) 0 (0) 100 1 s ω
ν = 300 Nms
H(t) is Heaviside function
FigA - zero value of angular momentum and different inertia moments of main body
Fig A Fig B
Fig4 - reorientation process at nonzero system angular momentum
30
__________________________________________________________
The main properties of the attitude stabilization and control of SC (and multirotor systems) have been examined
Research into attitude motion of the one-body-SC dual-spin SC and spider-type-SC is very complicated
Nontrivial and chaotic modes are possible in the SC attitude motion
Conclusion
- Slide 1
- Outline
- Part 1 - Introduction to Attitude Dynamics and Control
- Slide 4
- Spin stabilization
- Spin Stabilization Dual-Spin Spacecraft
- Spin Stabilization Dual-Spin Spacecraft (2)
- Spin Stabilization Dual-Spin Spacecraft (3)
- Spin Stabilization Dual-Spin Spacecraft (4)
- Gravity Gradient Stabilization
- Magnetic Stabilization
- Aerodynamic Stabilization
- Actuators
- Actuators (2)
- Actuators (3)
- Main Equations of Angular Motion of Rigid Body (Attitude Motion
- Main Properties of the Free Angular Motion of Rigid Body (Attit
- Main Properties of the Free Angular Motion of Rigid Body (Attit (2)
- Part 2 ndash Research Results
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
-
Main Equations of Angular Motion of Rigid Body(Attitude Motion of SC)
11
Euler dynamical equations
Euler kinematical equations
The study of the angular motion of the SC attitude dynamics is one of the main problems of rigid body systems dynamics in the classical mechanics
And vice versa
Tasks of analysis and synthesis of the rigid bodiesrsquo motion have important applications in the space-flight dynamics
Main Properties of the Free Angular Motion of Rigid Body(Attitude Motion of SC)
12
Louis Poinsot interpreacutetation
Inertia tensor with polhodes
--- notation by CDHall
Main Properties of the Free Angular Motion of Rigid Body(Attitude Motion of SC)
12
If we consider rigid body angular motion on the base of Hamilton dynamics than for rigid body motion we take pendulum phase structure
x=tetta (nutation) and
y = impulse (tetta) ~ d(tetta)dt
Pendulum phase space
Part 2 ndash Research Results
1 The magnetized dual-spin spacecraft attitude motion
2 The regular and chaotic dynamics of dual-spin spacecraft
3 The multi-rotor system and multi-spin spacecraft dynamics
13
14
Letrsquos consider an angular motion (about point O) of spider-type multiple rotor rigid bodies systems and
coaxial bodies systems
Mechanical models of multiple-rotor systems
Coaxial bodies system(dual-spin spacecraft)
Multirotor spiders(gyrostat-spacecrafts)
Number of rotors = N
Number of rotors = 6 Number of rotors = 1
1cos sin
cos
sin cos
sincos sin
cos
p q
p q
r p q
(1)
(2)
15
I1 The angular motion general equations
I The coaxial bodies system motion
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
cos sinP
P Q M Q
The coaxial top
I2 The angular motion equations of the magnetic DSSC and the coaxial Lagrange top
16
The single dipole model of the Earthrsquos magnetic field and the constant magnetic field vector corresponding to the circle equatorial orbit
The magnetic DSSC coordinate frames
17I3 The equations
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
2 2 2
2 1
0
T
x y zOx y z
T
orb orb
M M M
B m B m
oθ
θ
rbM m B
M
1 2
2 2
3 2
cos
cos
cos
OZ Ox
OZ Oy
OZ Oz
i k
j k
k k
2 2
2 1
2
0
Ap C B qr q Q
Bq A C pr p Q
C r B A pq M
orbQ B m
1
22 2 2 2 22
1 2 1 2 1 2
sin cos 1
2 2
T P
LI L l lT
A A A B C C
H H
cos sinP
P Q M Q
(6)
(5)
(4)
(3)
(2)
(1)
18I4 The integrals and solutions
2
2
2
1
2
23
x
y
z
K Ap
K KK Bq
K KK C r
K K
2
2
2
2 3
2
const
cos
z
z
L K C r
I I K
K C rL
K K K
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
2
2 2 22 2
1
2 2Ap Bq C r E C r TC
22 2 2 2 22 2A p B q C r K DT
2 1 2
22 21
2
22 2
Bq A C f q f q
C B C Ff q V E
A A B A A B
H B A B qf q V V
C A C
- AV Doroshin Exact Solutions in Attitude Dynamics of a Magnetic Dual-Spin Spacecraft and a Generalization of the Lagrange Top WSEAS Transactions on Systems Issue 10 Volume 12 (2013)
471-482
(11) (10)
(9)
(8) (7)
19I5 The analytical solution
The polhodes ellipsoid
2
2 2
22 2
2 1
1
1
q t H C A C x t SB A B
p t C B C x t FA A B
EAr t x t S t r t
A C C
2 20 0
2 20 0
sn
sn
i
i
R P c N t t I kx t e
R P c N t t I k
S E
The numerical integration (lines) and analytical (points) results
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075 q0=2 r0=583 [1s] K=50
[kgm2s] Q=100 [kgm2s2]
5
(13)
(12)
20I6 The analytical solution for Euler angles
orbB
K2K + ω timesK = mtimesK
K + ΩtimesK = 0
orbB
K 2Ω ω m
γ + Ωtimes γ = 0
1
2
3 2
t Ap t K
t Bq t K
C r t K
2cos
tg
t C r t K
Ap tt
Bq t
0
0
2 2
0 2 2 2 2
01
( ) ( )
( ) ( )
( )
t
t
t
t
Ap t Bq tt K dt
A p t B q t
t r t dtC
5
10 20 3003 052 08
The numerical integration (lines) and analytical (points) results for the directional cosines
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075
q0=2 r0=583 [1s] K=50 [km2s]
Q=100 [kgm2s2]
(19)
(20)
(18) (17)
(16)
(15)
(14)
21I7 Hamilton form of equations in the Andoyer-Deprit variables
(21)
(25)
(22)
(23)
(24)
1 C r
22
3 23
T T
T
L I Kl
I L I
K k K s K
K k
2
2
2
2 22
2 22
2
sin
cos
x
y
z
K Ap I L l
K Bq I L l
K C r L
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
22 2 2 2 22
1 2 1 2 1 2 2
sin cos 1
2 2
LI L l l LQ
A A A B C C I
H
22
(26)
Hamilton form of equations 2 2 2 1 1A B C A C
Equations (21) have heteroclinic solutions
Perturbations
0 0 L lM t f l t L t g t t dt
Melnikov function
(28)
The Melnikov function has the infinite number of simple roots This proves the fact of the motion chaotization at the presence of small harmonic perturbations
22 2 2 2
2 1
C B C EB
p t y t q t s k y t E r t y t t r tA A B B C C
0
sin cosN
n p n pn
Q t a n t b n t
22 2 2 2 2
20 0
1 2 1 2 1 2 2 20 1 0 1
sin cos 1
2 2
LI L l l L LQ Q Q t
A A A B C C I I
H H H H H
0 0 1 1
L L
L l L l
l l
L f l L gf f g g
l L l Ll f l L g
H H H H
0 0 00
cos sinN
ns n p n p
n
M t J a n t b n t
(27)
(26)
00 0 2
2
00 1 2 02
4 exp
exp 4
M aa E y t
ky t
Mt aE y a a a
k
23
2 l L I
I8 Numerical modeling Poincareacute sections mod 2 0pt
2 22 2 2 1 1 2 1 3 5
0 0 0 0
15 10 6 5 4[ ] 20 5 [ ] 075 [1 ] 1 5 20 [1]
) 5 004 ) 5 01 ) 10 01 ) 15 02
pA B C A C kg m I kg m s s a a a
a Q b Q c Q d Q
(a) (b)
(c) (d)
II The spider-type systems motion 24
m r K K K
1 2
3 4
5 6
4 2 m r
Ap p
Bq J I q I
Cr r
K K
ed
dt
Kω K M
12 56 34
34 12 56
56 34 12
ex
ey
ez
Ap I C B qr I q r M
Bq I A C pr I r p M
Cr I B A pq I p q M
4 2
4 2 4 2
iji j A A J I
B B J I C C J I
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i ex x
i e i ey y
i e i ez z
I p M M I p M M
I q M M I q M M
I r M M I r M M
(1)
(2)
(3)
(4)
II1 Angular momentum of the system in projections onto axes of the frame Oxyz
II2 The motion equations of the multirotor system
25
1 1
1 1
4 2
4 2 4 2
N Nij
il jl ll l
N N
l ll l
A A J NI
B B J NI C C J NI
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i el l lx l l lx
i e i el l ly l l ly
i e i el l lz l l lz
I p M M I p M M
I q M M I q M M
I r M M I r M M
0
1
2
3
cos 2
cos sin2
cos sin2
cos sin2
2 λ Θ λ
0
1
2
3
0
0
0
0
p q r
p r q
q r p
r q p
λ Θ
(4rsquo)
II3 The Euler parameters
(5)
26II4 The conjugate spinups and captures
Def1 Conjugate rotors are paired rotors located in the same layer on the opposite rays For example rotor 3N and rotor 4N are conjugate rotors (also rotor 12 and rotor 22 etc)
Def2 Conjugate spinup mean a process of spinning up conjugate rotors in opposite directions up to a desired value of relative angular velocity with the help of internal moments from main body Velocities of conjugate rotors will be equal in absolute value and opposite in sign
Def3 Rotor capture is an immediate deceleration of rotor relative angular velocity with the help of internal moment from the main body So rotor capture means an ldquoinstantaneous freezingrdquo of rotor with respect to the main body The capture can be performed with the help of gear meshing friction clutch or other methods
27
(6)
II6 Analytical solutions of motion equations
0e e ex y zM M M
A B C D
12 121
12 122
0
0
0
0
si
si
M if t tM
otherwise
M if t tM
otherwise
12 12 12sS M t I
1 12 2 12S S
1 1 12c c st t t
1 0
12
122
ISp
A IAS
A I
1 0 Conjugate spinup of rotors 1 2
Rotor 1 capture
Rotor 2 capture
2 2 1c c ct t t
1 2
121 2
0 0
c c
c c
t t tp IS
P t t tA I
Two serial captures of conjugate rotors bring to piecewise constant angular velocity of the main body
The main body performed the rotation about Ox axis by finite angle 12 2 1
c c
x
IS t t
A I
28
1 3 5 2 4 6
0 1 2 3
1 0
c c c c c c c cstart finish
c c c cstart start start start
t t t t t t t t
t t t t
0 1
2 3
2 2 2
cos sin2 2
sin sin2 2
c cstart start
c cstart start
c c c cstart finish finish start
t t t tPt t
t t t tQ Rt t
P Q R t t t T t t
1 2 t t t p P q Q r R
Letrsquos assume synchronically captures of coresponded conjugate rotors 1 2 3 4 5 6 and coincidence of the frame Oxyz initial position and the fixed frame OXYZ
Angular velocities between conjugate captures of rotors
Solutions of kinematic equations (5)
cos cos cosT
P Q R
T
e
The main body performed finite rotation about vector e by angle χ
(18)
(20)
(19)
(21)
29II7 Numerical simulation of reorientation process
const 0 1 135 246
i s cj jj j j
i s cj jj j j
jj
M M H t H t t H t t
M M H t H t t H t t
M j j
Two sets of results of numerical simulation
1 4 5(0) (0) (0) 0 (0) 100 1 s ω
ν = 300 Nms
H(t) is Heaviside function
FigA - zero value of angular momentum and different inertia moments of main body
Fig A Fig B
Fig4 - reorientation process at nonzero system angular momentum
30
__________________________________________________________
The main properties of the attitude stabilization and control of SC (and multirotor systems) have been examined
Research into attitude motion of the one-body-SC dual-spin SC and spider-type-SC is very complicated
Nontrivial and chaotic modes are possible in the SC attitude motion
Conclusion
- Slide 1
- Outline
- Part 1 - Introduction to Attitude Dynamics and Control
- Slide 4
- Spin stabilization
- Spin Stabilization Dual-Spin Spacecraft
- Spin Stabilization Dual-Spin Spacecraft (2)
- Spin Stabilization Dual-Spin Spacecraft (3)
- Spin Stabilization Dual-Spin Spacecraft (4)
- Gravity Gradient Stabilization
- Magnetic Stabilization
- Aerodynamic Stabilization
- Actuators
- Actuators (2)
- Actuators (3)
- Main Equations of Angular Motion of Rigid Body (Attitude Motion
- Main Properties of the Free Angular Motion of Rigid Body (Attit
- Main Properties of the Free Angular Motion of Rigid Body (Attit (2)
- Part 2 ndash Research Results
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
-
Main Properties of the Free Angular Motion of Rigid Body(Attitude Motion of SC)
12
Louis Poinsot interpreacutetation
Inertia tensor with polhodes
--- notation by CDHall
Main Properties of the Free Angular Motion of Rigid Body(Attitude Motion of SC)
12
If we consider rigid body angular motion on the base of Hamilton dynamics than for rigid body motion we take pendulum phase structure
x=tetta (nutation) and
y = impulse (tetta) ~ d(tetta)dt
Pendulum phase space
Part 2 ndash Research Results
1 The magnetized dual-spin spacecraft attitude motion
2 The regular and chaotic dynamics of dual-spin spacecraft
3 The multi-rotor system and multi-spin spacecraft dynamics
13
14
Letrsquos consider an angular motion (about point O) of spider-type multiple rotor rigid bodies systems and
coaxial bodies systems
Mechanical models of multiple-rotor systems
Coaxial bodies system(dual-spin spacecraft)
Multirotor spiders(gyrostat-spacecrafts)
Number of rotors = N
Number of rotors = 6 Number of rotors = 1
1cos sin
cos
sin cos
sincos sin
cos
p q
p q
r p q
(1)
(2)
15
I1 The angular motion general equations
I The coaxial bodies system motion
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
cos sinP
P Q M Q
The coaxial top
I2 The angular motion equations of the magnetic DSSC and the coaxial Lagrange top
16
The single dipole model of the Earthrsquos magnetic field and the constant magnetic field vector corresponding to the circle equatorial orbit
The magnetic DSSC coordinate frames
17I3 The equations
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
2 2 2
2 1
0
T
x y zOx y z
T
orb orb
M M M
B m B m
oθ
θ
rbM m B
M
1 2
2 2
3 2
cos
cos
cos
OZ Ox
OZ Oy
OZ Oz
i k
j k
k k
2 2
2 1
2
0
Ap C B qr q Q
Bq A C pr p Q
C r B A pq M
orbQ B m
1
22 2 2 2 22
1 2 1 2 1 2
sin cos 1
2 2
T P
LI L l lT
A A A B C C
H H
cos sinP
P Q M Q
(6)
(5)
(4)
(3)
(2)
(1)
18I4 The integrals and solutions
2
2
2
1
2
23
x
y
z
K Ap
K KK Bq
K KK C r
K K
2
2
2
2 3
2
const
cos
z
z
L K C r
I I K
K C rL
K K K
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
2
2 2 22 2
1
2 2Ap Bq C r E C r TC
22 2 2 2 22 2A p B q C r K DT
2 1 2
22 21
2
22 2
Bq A C f q f q
C B C Ff q V E
A A B A A B
H B A B qf q V V
C A C
- AV Doroshin Exact Solutions in Attitude Dynamics of a Magnetic Dual-Spin Spacecraft and a Generalization of the Lagrange Top WSEAS Transactions on Systems Issue 10 Volume 12 (2013)
471-482
(11) (10)
(9)
(8) (7)
19I5 The analytical solution
The polhodes ellipsoid
2
2 2
22 2
2 1
1
1
q t H C A C x t SB A B
p t C B C x t FA A B
EAr t x t S t r t
A C C
2 20 0
2 20 0
sn
sn
i
i
R P c N t t I kx t e
R P c N t t I k
S E
The numerical integration (lines) and analytical (points) results
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075 q0=2 r0=583 [1s] K=50
[kgm2s] Q=100 [kgm2s2]
5
(13)
(12)
20I6 The analytical solution for Euler angles
orbB
K2K + ω timesK = mtimesK
K + ΩtimesK = 0
orbB
K 2Ω ω m
γ + Ωtimes γ = 0
1
2
3 2
t Ap t K
t Bq t K
C r t K
2cos
tg
t C r t K
Ap tt
Bq t
0
0
2 2
0 2 2 2 2
01
( ) ( )
( ) ( )
( )
t
t
t
t
Ap t Bq tt K dt
A p t B q t
t r t dtC
5
10 20 3003 052 08
The numerical integration (lines) and analytical (points) results for the directional cosines
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075
q0=2 r0=583 [1s] K=50 [km2s]
Q=100 [kgm2s2]
(19)
(20)
(18) (17)
(16)
(15)
(14)
21I7 Hamilton form of equations in the Andoyer-Deprit variables
(21)
(25)
(22)
(23)
(24)
1 C r
22
3 23
T T
T
L I Kl
I L I
K k K s K
K k
2
2
2
2 22
2 22
2
sin
cos
x
y
z
K Ap I L l
K Bq I L l
K C r L
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
22 2 2 2 22
1 2 1 2 1 2 2
sin cos 1
2 2
LI L l l LQ
A A A B C C I
H
22
(26)
Hamilton form of equations 2 2 2 1 1A B C A C
Equations (21) have heteroclinic solutions
Perturbations
0 0 L lM t f l t L t g t t dt
Melnikov function
(28)
The Melnikov function has the infinite number of simple roots This proves the fact of the motion chaotization at the presence of small harmonic perturbations
22 2 2 2
2 1
C B C EB
p t y t q t s k y t E r t y t t r tA A B B C C
0
sin cosN
n p n pn
Q t a n t b n t
22 2 2 2 2
20 0
1 2 1 2 1 2 2 20 1 0 1
sin cos 1
2 2
LI L l l L LQ Q Q t
A A A B C C I I
H H H H H
0 0 1 1
L L
L l L l
l l
L f l L gf f g g
l L l Ll f l L g
H H H H
0 0 00
cos sinN
ns n p n p
n
M t J a n t b n t
(27)
(26)
00 0 2
2
00 1 2 02
4 exp
exp 4
M aa E y t
ky t
Mt aE y a a a
k
23
2 l L I
I8 Numerical modeling Poincareacute sections mod 2 0pt
2 22 2 2 1 1 2 1 3 5
0 0 0 0
15 10 6 5 4[ ] 20 5 [ ] 075 [1 ] 1 5 20 [1]
) 5 004 ) 5 01 ) 10 01 ) 15 02
pA B C A C kg m I kg m s s a a a
a Q b Q c Q d Q
(a) (b)
(c) (d)
II The spider-type systems motion 24
m r K K K
1 2
3 4
5 6
4 2 m r
Ap p
Bq J I q I
Cr r
K K
ed
dt
Kω K M
12 56 34
34 12 56
56 34 12
ex
ey
ez
Ap I C B qr I q r M
Bq I A C pr I r p M
Cr I B A pq I p q M
4 2
4 2 4 2
iji j A A J I
B B J I C C J I
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i ex x
i e i ey y
i e i ez z
I p M M I p M M
I q M M I q M M
I r M M I r M M
(1)
(2)
(3)
(4)
II1 Angular momentum of the system in projections onto axes of the frame Oxyz
II2 The motion equations of the multirotor system
25
1 1
1 1
4 2
4 2 4 2
N Nij
il jl ll l
N N
l ll l
A A J NI
B B J NI C C J NI
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i el l lx l l lx
i e i el l ly l l ly
i e i el l lz l l lz
I p M M I p M M
I q M M I q M M
I r M M I r M M
0
1
2
3
cos 2
cos sin2
cos sin2
cos sin2
2 λ Θ λ
0
1
2
3
0
0
0
0
p q r
p r q
q r p
r q p
λ Θ
(4rsquo)
II3 The Euler parameters
(5)
26II4 The conjugate spinups and captures
Def1 Conjugate rotors are paired rotors located in the same layer on the opposite rays For example rotor 3N and rotor 4N are conjugate rotors (also rotor 12 and rotor 22 etc)
Def2 Conjugate spinup mean a process of spinning up conjugate rotors in opposite directions up to a desired value of relative angular velocity with the help of internal moments from main body Velocities of conjugate rotors will be equal in absolute value and opposite in sign
Def3 Rotor capture is an immediate deceleration of rotor relative angular velocity with the help of internal moment from the main body So rotor capture means an ldquoinstantaneous freezingrdquo of rotor with respect to the main body The capture can be performed with the help of gear meshing friction clutch or other methods
27
(6)
II6 Analytical solutions of motion equations
0e e ex y zM M M
A B C D
12 121
12 122
0
0
0
0
si
si
M if t tM
otherwise
M if t tM
otherwise
12 12 12sS M t I
1 12 2 12S S
1 1 12c c st t t
1 0
12
122
ISp
A IAS
A I
1 0 Conjugate spinup of rotors 1 2
Rotor 1 capture
Rotor 2 capture
2 2 1c c ct t t
1 2
121 2
0 0
c c
c c
t t tp IS
P t t tA I
Two serial captures of conjugate rotors bring to piecewise constant angular velocity of the main body
The main body performed the rotation about Ox axis by finite angle 12 2 1
c c
x
IS t t
A I
28
1 3 5 2 4 6
0 1 2 3
1 0
c c c c c c c cstart finish
c c c cstart start start start
t t t t t t t t
t t t t
0 1
2 3
2 2 2
cos sin2 2
sin sin2 2
c cstart start
c cstart start
c c c cstart finish finish start
t t t tPt t
t t t tQ Rt t
P Q R t t t T t t
1 2 t t t p P q Q r R
Letrsquos assume synchronically captures of coresponded conjugate rotors 1 2 3 4 5 6 and coincidence of the frame Oxyz initial position and the fixed frame OXYZ
Angular velocities between conjugate captures of rotors
Solutions of kinematic equations (5)
cos cos cosT
P Q R
T
e
The main body performed finite rotation about vector e by angle χ
(18)
(20)
(19)
(21)
29II7 Numerical simulation of reorientation process
const 0 1 135 246
i s cj jj j j
i s cj jj j j
jj
M M H t H t t H t t
M M H t H t t H t t
M j j
Two sets of results of numerical simulation
1 4 5(0) (0) (0) 0 (0) 100 1 s ω
ν = 300 Nms
H(t) is Heaviside function
FigA - zero value of angular momentum and different inertia moments of main body
Fig A Fig B
Fig4 - reorientation process at nonzero system angular momentum
30
__________________________________________________________
The main properties of the attitude stabilization and control of SC (and multirotor systems) have been examined
Research into attitude motion of the one-body-SC dual-spin SC and spider-type-SC is very complicated
Nontrivial and chaotic modes are possible in the SC attitude motion
Conclusion
- Slide 1
- Outline
- Part 1 - Introduction to Attitude Dynamics and Control
- Slide 4
- Spin stabilization
- Spin Stabilization Dual-Spin Spacecraft
- Spin Stabilization Dual-Spin Spacecraft (2)
- Spin Stabilization Dual-Spin Spacecraft (3)
- Spin Stabilization Dual-Spin Spacecraft (4)
- Gravity Gradient Stabilization
- Magnetic Stabilization
- Aerodynamic Stabilization
- Actuators
- Actuators (2)
- Actuators (3)
- Main Equations of Angular Motion of Rigid Body (Attitude Motion
- Main Properties of the Free Angular Motion of Rigid Body (Attit
- Main Properties of the Free Angular Motion of Rigid Body (Attit (2)
- Part 2 ndash Research Results
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
-
Main Properties of the Free Angular Motion of Rigid Body(Attitude Motion of SC)
12
If we consider rigid body angular motion on the base of Hamilton dynamics than for rigid body motion we take pendulum phase structure
x=tetta (nutation) and
y = impulse (tetta) ~ d(tetta)dt
Pendulum phase space
Part 2 ndash Research Results
1 The magnetized dual-spin spacecraft attitude motion
2 The regular and chaotic dynamics of dual-spin spacecraft
3 The multi-rotor system and multi-spin spacecraft dynamics
13
14
Letrsquos consider an angular motion (about point O) of spider-type multiple rotor rigid bodies systems and
coaxial bodies systems
Mechanical models of multiple-rotor systems
Coaxial bodies system(dual-spin spacecraft)
Multirotor spiders(gyrostat-spacecrafts)
Number of rotors = N
Number of rotors = 6 Number of rotors = 1
1cos sin
cos
sin cos
sincos sin
cos
p q
p q
r p q
(1)
(2)
15
I1 The angular motion general equations
I The coaxial bodies system motion
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
cos sinP
P Q M Q
The coaxial top
I2 The angular motion equations of the magnetic DSSC and the coaxial Lagrange top
16
The single dipole model of the Earthrsquos magnetic field and the constant magnetic field vector corresponding to the circle equatorial orbit
The magnetic DSSC coordinate frames
17I3 The equations
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
2 2 2
2 1
0
T
x y zOx y z
T
orb orb
M M M
B m B m
oθ
θ
rbM m B
M
1 2
2 2
3 2
cos
cos
cos
OZ Ox
OZ Oy
OZ Oz
i k
j k
k k
2 2
2 1
2
0
Ap C B qr q Q
Bq A C pr p Q
C r B A pq M
orbQ B m
1
22 2 2 2 22
1 2 1 2 1 2
sin cos 1
2 2
T P
LI L l lT
A A A B C C
H H
cos sinP
P Q M Q
(6)
(5)
(4)
(3)
(2)
(1)
18I4 The integrals and solutions
2
2
2
1
2
23
x
y
z
K Ap
K KK Bq
K KK C r
K K
2
2
2
2 3
2
const
cos
z
z
L K C r
I I K
K C rL
K K K
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
2
2 2 22 2
1
2 2Ap Bq C r E C r TC
22 2 2 2 22 2A p B q C r K DT
2 1 2
22 21
2
22 2
Bq A C f q f q
C B C Ff q V E
A A B A A B
H B A B qf q V V
C A C
- AV Doroshin Exact Solutions in Attitude Dynamics of a Magnetic Dual-Spin Spacecraft and a Generalization of the Lagrange Top WSEAS Transactions on Systems Issue 10 Volume 12 (2013)
471-482
(11) (10)
(9)
(8) (7)
19I5 The analytical solution
The polhodes ellipsoid
2
2 2
22 2
2 1
1
1
q t H C A C x t SB A B
p t C B C x t FA A B
EAr t x t S t r t
A C C
2 20 0
2 20 0
sn
sn
i
i
R P c N t t I kx t e
R P c N t t I k
S E
The numerical integration (lines) and analytical (points) results
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075 q0=2 r0=583 [1s] K=50
[kgm2s] Q=100 [kgm2s2]
5
(13)
(12)
20I6 The analytical solution for Euler angles
orbB
K2K + ω timesK = mtimesK
K + ΩtimesK = 0
orbB
K 2Ω ω m
γ + Ωtimes γ = 0
1
2
3 2
t Ap t K
t Bq t K
C r t K
2cos
tg
t C r t K
Ap tt
Bq t
0
0
2 2
0 2 2 2 2
01
( ) ( )
( ) ( )
( )
t
t
t
t
Ap t Bq tt K dt
A p t B q t
t r t dtC
5
10 20 3003 052 08
The numerical integration (lines) and analytical (points) results for the directional cosines
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075
q0=2 r0=583 [1s] K=50 [km2s]
Q=100 [kgm2s2]
(19)
(20)
(18) (17)
(16)
(15)
(14)
21I7 Hamilton form of equations in the Andoyer-Deprit variables
(21)
(25)
(22)
(23)
(24)
1 C r
22
3 23
T T
T
L I Kl
I L I
K k K s K
K k
2
2
2
2 22
2 22
2
sin
cos
x
y
z
K Ap I L l
K Bq I L l
K C r L
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
22 2 2 2 22
1 2 1 2 1 2 2
sin cos 1
2 2
LI L l l LQ
A A A B C C I
H
22
(26)
Hamilton form of equations 2 2 2 1 1A B C A C
Equations (21) have heteroclinic solutions
Perturbations
0 0 L lM t f l t L t g t t dt
Melnikov function
(28)
The Melnikov function has the infinite number of simple roots This proves the fact of the motion chaotization at the presence of small harmonic perturbations
22 2 2 2
2 1
C B C EB
p t y t q t s k y t E r t y t t r tA A B B C C
0
sin cosN
n p n pn
Q t a n t b n t
22 2 2 2 2
20 0
1 2 1 2 1 2 2 20 1 0 1
sin cos 1
2 2
LI L l l L LQ Q Q t
A A A B C C I I
H H H H H
0 0 1 1
L L
L l L l
l l
L f l L gf f g g
l L l Ll f l L g
H H H H
0 0 00
cos sinN
ns n p n p
n
M t J a n t b n t
(27)
(26)
00 0 2
2
00 1 2 02
4 exp
exp 4
M aa E y t
ky t
Mt aE y a a a
k
23
2 l L I
I8 Numerical modeling Poincareacute sections mod 2 0pt
2 22 2 2 1 1 2 1 3 5
0 0 0 0
15 10 6 5 4[ ] 20 5 [ ] 075 [1 ] 1 5 20 [1]
) 5 004 ) 5 01 ) 10 01 ) 15 02
pA B C A C kg m I kg m s s a a a
a Q b Q c Q d Q
(a) (b)
(c) (d)
II The spider-type systems motion 24
m r K K K
1 2
3 4
5 6
4 2 m r
Ap p
Bq J I q I
Cr r
K K
ed
dt
Kω K M
12 56 34
34 12 56
56 34 12
ex
ey
ez
Ap I C B qr I q r M
Bq I A C pr I r p M
Cr I B A pq I p q M
4 2
4 2 4 2
iji j A A J I
B B J I C C J I
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i ex x
i e i ey y
i e i ez z
I p M M I p M M
I q M M I q M M
I r M M I r M M
(1)
(2)
(3)
(4)
II1 Angular momentum of the system in projections onto axes of the frame Oxyz
II2 The motion equations of the multirotor system
25
1 1
1 1
4 2
4 2 4 2
N Nij
il jl ll l
N N
l ll l
A A J NI
B B J NI C C J NI
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i el l lx l l lx
i e i el l ly l l ly
i e i el l lz l l lz
I p M M I p M M
I q M M I q M M
I r M M I r M M
0
1
2
3
cos 2
cos sin2
cos sin2
cos sin2
2 λ Θ λ
0
1
2
3
0
0
0
0
p q r
p r q
q r p
r q p
λ Θ
(4rsquo)
II3 The Euler parameters
(5)
26II4 The conjugate spinups and captures
Def1 Conjugate rotors are paired rotors located in the same layer on the opposite rays For example rotor 3N and rotor 4N are conjugate rotors (also rotor 12 and rotor 22 etc)
Def2 Conjugate spinup mean a process of spinning up conjugate rotors in opposite directions up to a desired value of relative angular velocity with the help of internal moments from main body Velocities of conjugate rotors will be equal in absolute value and opposite in sign
Def3 Rotor capture is an immediate deceleration of rotor relative angular velocity with the help of internal moment from the main body So rotor capture means an ldquoinstantaneous freezingrdquo of rotor with respect to the main body The capture can be performed with the help of gear meshing friction clutch or other methods
27
(6)
II6 Analytical solutions of motion equations
0e e ex y zM M M
A B C D
12 121
12 122
0
0
0
0
si
si
M if t tM
otherwise
M if t tM
otherwise
12 12 12sS M t I
1 12 2 12S S
1 1 12c c st t t
1 0
12
122
ISp
A IAS
A I
1 0 Conjugate spinup of rotors 1 2
Rotor 1 capture
Rotor 2 capture
2 2 1c c ct t t
1 2
121 2
0 0
c c
c c
t t tp IS
P t t tA I
Two serial captures of conjugate rotors bring to piecewise constant angular velocity of the main body
The main body performed the rotation about Ox axis by finite angle 12 2 1
c c
x
IS t t
A I
28
1 3 5 2 4 6
0 1 2 3
1 0
c c c c c c c cstart finish
c c c cstart start start start
t t t t t t t t
t t t t
0 1
2 3
2 2 2
cos sin2 2
sin sin2 2
c cstart start
c cstart start
c c c cstart finish finish start
t t t tPt t
t t t tQ Rt t
P Q R t t t T t t
1 2 t t t p P q Q r R
Letrsquos assume synchronically captures of coresponded conjugate rotors 1 2 3 4 5 6 and coincidence of the frame Oxyz initial position and the fixed frame OXYZ
Angular velocities between conjugate captures of rotors
Solutions of kinematic equations (5)
cos cos cosT
P Q R
T
e
The main body performed finite rotation about vector e by angle χ
(18)
(20)
(19)
(21)
29II7 Numerical simulation of reorientation process
const 0 1 135 246
i s cj jj j j
i s cj jj j j
jj
M M H t H t t H t t
M M H t H t t H t t
M j j
Two sets of results of numerical simulation
1 4 5(0) (0) (0) 0 (0) 100 1 s ω
ν = 300 Nms
H(t) is Heaviside function
FigA - zero value of angular momentum and different inertia moments of main body
Fig A Fig B
Fig4 - reorientation process at nonzero system angular momentum
30
__________________________________________________________
The main properties of the attitude stabilization and control of SC (and multirotor systems) have been examined
Research into attitude motion of the one-body-SC dual-spin SC and spider-type-SC is very complicated
Nontrivial and chaotic modes are possible in the SC attitude motion
Conclusion
- Slide 1
- Outline
- Part 1 - Introduction to Attitude Dynamics and Control
- Slide 4
- Spin stabilization
- Spin Stabilization Dual-Spin Spacecraft
- Spin Stabilization Dual-Spin Spacecraft (2)
- Spin Stabilization Dual-Spin Spacecraft (3)
- Spin Stabilization Dual-Spin Spacecraft (4)
- Gravity Gradient Stabilization
- Magnetic Stabilization
- Aerodynamic Stabilization
- Actuators
- Actuators (2)
- Actuators (3)
- Main Equations of Angular Motion of Rigid Body (Attitude Motion
- Main Properties of the Free Angular Motion of Rigid Body (Attit
- Main Properties of the Free Angular Motion of Rigid Body (Attit (2)
- Part 2 ndash Research Results
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
-
Part 2 ndash Research Results
1 The magnetized dual-spin spacecraft attitude motion
2 The regular and chaotic dynamics of dual-spin spacecraft
3 The multi-rotor system and multi-spin spacecraft dynamics
13
14
Letrsquos consider an angular motion (about point O) of spider-type multiple rotor rigid bodies systems and
coaxial bodies systems
Mechanical models of multiple-rotor systems
Coaxial bodies system(dual-spin spacecraft)
Multirotor spiders(gyrostat-spacecrafts)
Number of rotors = N
Number of rotors = 6 Number of rotors = 1
1cos sin
cos
sin cos
sincos sin
cos
p q
p q
r p q
(1)
(2)
15
I1 The angular motion general equations
I The coaxial bodies system motion
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
cos sinP
P Q M Q
The coaxial top
I2 The angular motion equations of the magnetic DSSC and the coaxial Lagrange top
16
The single dipole model of the Earthrsquos magnetic field and the constant magnetic field vector corresponding to the circle equatorial orbit
The magnetic DSSC coordinate frames
17I3 The equations
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
2 2 2
2 1
0
T
x y zOx y z
T
orb orb
M M M
B m B m
oθ
θ
rbM m B
M
1 2
2 2
3 2
cos
cos
cos
OZ Ox
OZ Oy
OZ Oz
i k
j k
k k
2 2
2 1
2
0
Ap C B qr q Q
Bq A C pr p Q
C r B A pq M
orbQ B m
1
22 2 2 2 22
1 2 1 2 1 2
sin cos 1
2 2
T P
LI L l lT
A A A B C C
H H
cos sinP
P Q M Q
(6)
(5)
(4)
(3)
(2)
(1)
18I4 The integrals and solutions
2
2
2
1
2
23
x
y
z
K Ap
K KK Bq
K KK C r
K K
2
2
2
2 3
2
const
cos
z
z
L K C r
I I K
K C rL
K K K
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
2
2 2 22 2
1
2 2Ap Bq C r E C r TC
22 2 2 2 22 2A p B q C r K DT
2 1 2
22 21
2
22 2
Bq A C f q f q
C B C Ff q V E
A A B A A B
H B A B qf q V V
C A C
- AV Doroshin Exact Solutions in Attitude Dynamics of a Magnetic Dual-Spin Spacecraft and a Generalization of the Lagrange Top WSEAS Transactions on Systems Issue 10 Volume 12 (2013)
471-482
(11) (10)
(9)
(8) (7)
19I5 The analytical solution
The polhodes ellipsoid
2
2 2
22 2
2 1
1
1
q t H C A C x t SB A B
p t C B C x t FA A B
EAr t x t S t r t
A C C
2 20 0
2 20 0
sn
sn
i
i
R P c N t t I kx t e
R P c N t t I k
S E
The numerical integration (lines) and analytical (points) results
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075 q0=2 r0=583 [1s] K=50
[kgm2s] Q=100 [kgm2s2]
5
(13)
(12)
20I6 The analytical solution for Euler angles
orbB
K2K + ω timesK = mtimesK
K + ΩtimesK = 0
orbB
K 2Ω ω m
γ + Ωtimes γ = 0
1
2
3 2
t Ap t K
t Bq t K
C r t K
2cos
tg
t C r t K
Ap tt
Bq t
0
0
2 2
0 2 2 2 2
01
( ) ( )
( ) ( )
( )
t
t
t
t
Ap t Bq tt K dt
A p t B q t
t r t dtC
5
10 20 3003 052 08
The numerical integration (lines) and analytical (points) results for the directional cosines
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075
q0=2 r0=583 [1s] K=50 [km2s]
Q=100 [kgm2s2]
(19)
(20)
(18) (17)
(16)
(15)
(14)
21I7 Hamilton form of equations in the Andoyer-Deprit variables
(21)
(25)
(22)
(23)
(24)
1 C r
22
3 23
T T
T
L I Kl
I L I
K k K s K
K k
2
2
2
2 22
2 22
2
sin
cos
x
y
z
K Ap I L l
K Bq I L l
K C r L
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
22 2 2 2 22
1 2 1 2 1 2 2
sin cos 1
2 2
LI L l l LQ
A A A B C C I
H
22
(26)
Hamilton form of equations 2 2 2 1 1A B C A C
Equations (21) have heteroclinic solutions
Perturbations
0 0 L lM t f l t L t g t t dt
Melnikov function
(28)
The Melnikov function has the infinite number of simple roots This proves the fact of the motion chaotization at the presence of small harmonic perturbations
22 2 2 2
2 1
C B C EB
p t y t q t s k y t E r t y t t r tA A B B C C
0
sin cosN
n p n pn
Q t a n t b n t
22 2 2 2 2
20 0
1 2 1 2 1 2 2 20 1 0 1
sin cos 1
2 2
LI L l l L LQ Q Q t
A A A B C C I I
H H H H H
0 0 1 1
L L
L l L l
l l
L f l L gf f g g
l L l Ll f l L g
H H H H
0 0 00
cos sinN
ns n p n p
n
M t J a n t b n t
(27)
(26)
00 0 2
2
00 1 2 02
4 exp
exp 4
M aa E y t
ky t
Mt aE y a a a
k
23
2 l L I
I8 Numerical modeling Poincareacute sections mod 2 0pt
2 22 2 2 1 1 2 1 3 5
0 0 0 0
15 10 6 5 4[ ] 20 5 [ ] 075 [1 ] 1 5 20 [1]
) 5 004 ) 5 01 ) 10 01 ) 15 02
pA B C A C kg m I kg m s s a a a
a Q b Q c Q d Q
(a) (b)
(c) (d)
II The spider-type systems motion 24
m r K K K
1 2
3 4
5 6
4 2 m r
Ap p
Bq J I q I
Cr r
K K
ed
dt
Kω K M
12 56 34
34 12 56
56 34 12
ex
ey
ez
Ap I C B qr I q r M
Bq I A C pr I r p M
Cr I B A pq I p q M
4 2
4 2 4 2
iji j A A J I
B B J I C C J I
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i ex x
i e i ey y
i e i ez z
I p M M I p M M
I q M M I q M M
I r M M I r M M
(1)
(2)
(3)
(4)
II1 Angular momentum of the system in projections onto axes of the frame Oxyz
II2 The motion equations of the multirotor system
25
1 1
1 1
4 2
4 2 4 2
N Nij
il jl ll l
N N
l ll l
A A J NI
B B J NI C C J NI
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i el l lx l l lx
i e i el l ly l l ly
i e i el l lz l l lz
I p M M I p M M
I q M M I q M M
I r M M I r M M
0
1
2
3
cos 2
cos sin2
cos sin2
cos sin2
2 λ Θ λ
0
1
2
3
0
0
0
0
p q r
p r q
q r p
r q p
λ Θ
(4rsquo)
II3 The Euler parameters
(5)
26II4 The conjugate spinups and captures
Def1 Conjugate rotors are paired rotors located in the same layer on the opposite rays For example rotor 3N and rotor 4N are conjugate rotors (also rotor 12 and rotor 22 etc)
Def2 Conjugate spinup mean a process of spinning up conjugate rotors in opposite directions up to a desired value of relative angular velocity with the help of internal moments from main body Velocities of conjugate rotors will be equal in absolute value and opposite in sign
Def3 Rotor capture is an immediate deceleration of rotor relative angular velocity with the help of internal moment from the main body So rotor capture means an ldquoinstantaneous freezingrdquo of rotor with respect to the main body The capture can be performed with the help of gear meshing friction clutch or other methods
27
(6)
II6 Analytical solutions of motion equations
0e e ex y zM M M
A B C D
12 121
12 122
0
0
0
0
si
si
M if t tM
otherwise
M if t tM
otherwise
12 12 12sS M t I
1 12 2 12S S
1 1 12c c st t t
1 0
12
122
ISp
A IAS
A I
1 0 Conjugate spinup of rotors 1 2
Rotor 1 capture
Rotor 2 capture
2 2 1c c ct t t
1 2
121 2
0 0
c c
c c
t t tp IS
P t t tA I
Two serial captures of conjugate rotors bring to piecewise constant angular velocity of the main body
The main body performed the rotation about Ox axis by finite angle 12 2 1
c c
x
IS t t
A I
28
1 3 5 2 4 6
0 1 2 3
1 0
c c c c c c c cstart finish
c c c cstart start start start
t t t t t t t t
t t t t
0 1
2 3
2 2 2
cos sin2 2
sin sin2 2
c cstart start
c cstart start
c c c cstart finish finish start
t t t tPt t
t t t tQ Rt t
P Q R t t t T t t
1 2 t t t p P q Q r R
Letrsquos assume synchronically captures of coresponded conjugate rotors 1 2 3 4 5 6 and coincidence of the frame Oxyz initial position and the fixed frame OXYZ
Angular velocities between conjugate captures of rotors
Solutions of kinematic equations (5)
cos cos cosT
P Q R
T
e
The main body performed finite rotation about vector e by angle χ
(18)
(20)
(19)
(21)
29II7 Numerical simulation of reorientation process
const 0 1 135 246
i s cj jj j j
i s cj jj j j
jj
M M H t H t t H t t
M M H t H t t H t t
M j j
Two sets of results of numerical simulation
1 4 5(0) (0) (0) 0 (0) 100 1 s ω
ν = 300 Nms
H(t) is Heaviside function
FigA - zero value of angular momentum and different inertia moments of main body
Fig A Fig B
Fig4 - reorientation process at nonzero system angular momentum
30
__________________________________________________________
The main properties of the attitude stabilization and control of SC (and multirotor systems) have been examined
Research into attitude motion of the one-body-SC dual-spin SC and spider-type-SC is very complicated
Nontrivial and chaotic modes are possible in the SC attitude motion
Conclusion
- Slide 1
- Outline
- Part 1 - Introduction to Attitude Dynamics and Control
- Slide 4
- Spin stabilization
- Spin Stabilization Dual-Spin Spacecraft
- Spin Stabilization Dual-Spin Spacecraft (2)
- Spin Stabilization Dual-Spin Spacecraft (3)
- Spin Stabilization Dual-Spin Spacecraft (4)
- Gravity Gradient Stabilization
- Magnetic Stabilization
- Aerodynamic Stabilization
- Actuators
- Actuators (2)
- Actuators (3)
- Main Equations of Angular Motion of Rigid Body (Attitude Motion
- Main Properties of the Free Angular Motion of Rigid Body (Attit
- Main Properties of the Free Angular Motion of Rigid Body (Attit (2)
- Part 2 ndash Research Results
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
-
14
Letrsquos consider an angular motion (about point O) of spider-type multiple rotor rigid bodies systems and
coaxial bodies systems
Mechanical models of multiple-rotor systems
Coaxial bodies system(dual-spin spacecraft)
Multirotor spiders(gyrostat-spacecrafts)
Number of rotors = N
Number of rotors = 6 Number of rotors = 1
1cos sin
cos
sin cos
sincos sin
cos
p q
p q
r p q
(1)
(2)
15
I1 The angular motion general equations
I The coaxial bodies system motion
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
cos sinP
P Q M Q
The coaxial top
I2 The angular motion equations of the magnetic DSSC and the coaxial Lagrange top
16
The single dipole model of the Earthrsquos magnetic field and the constant magnetic field vector corresponding to the circle equatorial orbit
The magnetic DSSC coordinate frames
17I3 The equations
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
2 2 2
2 1
0
T
x y zOx y z
T
orb orb
M M M
B m B m
oθ
θ
rbM m B
M
1 2
2 2
3 2
cos
cos
cos
OZ Ox
OZ Oy
OZ Oz
i k
j k
k k
2 2
2 1
2
0
Ap C B qr q Q
Bq A C pr p Q
C r B A pq M
orbQ B m
1
22 2 2 2 22
1 2 1 2 1 2
sin cos 1
2 2
T P
LI L l lT
A A A B C C
H H
cos sinP
P Q M Q
(6)
(5)
(4)
(3)
(2)
(1)
18I4 The integrals and solutions
2
2
2
1
2
23
x
y
z
K Ap
K KK Bq
K KK C r
K K
2
2
2
2 3
2
const
cos
z
z
L K C r
I I K
K C rL
K K K
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
2
2 2 22 2
1
2 2Ap Bq C r E C r TC
22 2 2 2 22 2A p B q C r K DT
2 1 2
22 21
2
22 2
Bq A C f q f q
C B C Ff q V E
A A B A A B
H B A B qf q V V
C A C
- AV Doroshin Exact Solutions in Attitude Dynamics of a Magnetic Dual-Spin Spacecraft and a Generalization of the Lagrange Top WSEAS Transactions on Systems Issue 10 Volume 12 (2013)
471-482
(11) (10)
(9)
(8) (7)
19I5 The analytical solution
The polhodes ellipsoid
2
2 2
22 2
2 1
1
1
q t H C A C x t SB A B
p t C B C x t FA A B
EAr t x t S t r t
A C C
2 20 0
2 20 0
sn
sn
i
i
R P c N t t I kx t e
R P c N t t I k
S E
The numerical integration (lines) and analytical (points) results
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075 q0=2 r0=583 [1s] K=50
[kgm2s] Q=100 [kgm2s2]
5
(13)
(12)
20I6 The analytical solution for Euler angles
orbB
K2K + ω timesK = mtimesK
K + ΩtimesK = 0
orbB
K 2Ω ω m
γ + Ωtimes γ = 0
1
2
3 2
t Ap t K
t Bq t K
C r t K
2cos
tg
t C r t K
Ap tt
Bq t
0
0
2 2
0 2 2 2 2
01
( ) ( )
( ) ( )
( )
t
t
t
t
Ap t Bq tt K dt
A p t B q t
t r t dtC
5
10 20 3003 052 08
The numerical integration (lines) and analytical (points) results for the directional cosines
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075
q0=2 r0=583 [1s] K=50 [km2s]
Q=100 [kgm2s2]
(19)
(20)
(18) (17)
(16)
(15)
(14)
21I7 Hamilton form of equations in the Andoyer-Deprit variables
(21)
(25)
(22)
(23)
(24)
1 C r
22
3 23
T T
T
L I Kl
I L I
K k K s K
K k
2
2
2
2 22
2 22
2
sin
cos
x
y
z
K Ap I L l
K Bq I L l
K C r L
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
22 2 2 2 22
1 2 1 2 1 2 2
sin cos 1
2 2
LI L l l LQ
A A A B C C I
H
22
(26)
Hamilton form of equations 2 2 2 1 1A B C A C
Equations (21) have heteroclinic solutions
Perturbations
0 0 L lM t f l t L t g t t dt
Melnikov function
(28)
The Melnikov function has the infinite number of simple roots This proves the fact of the motion chaotization at the presence of small harmonic perturbations
22 2 2 2
2 1
C B C EB
p t y t q t s k y t E r t y t t r tA A B B C C
0
sin cosN
n p n pn
Q t a n t b n t
22 2 2 2 2
20 0
1 2 1 2 1 2 2 20 1 0 1
sin cos 1
2 2
LI L l l L LQ Q Q t
A A A B C C I I
H H H H H
0 0 1 1
L L
L l L l
l l
L f l L gf f g g
l L l Ll f l L g
H H H H
0 0 00
cos sinN
ns n p n p
n
M t J a n t b n t
(27)
(26)
00 0 2
2
00 1 2 02
4 exp
exp 4
M aa E y t
ky t
Mt aE y a a a
k
23
2 l L I
I8 Numerical modeling Poincareacute sections mod 2 0pt
2 22 2 2 1 1 2 1 3 5
0 0 0 0
15 10 6 5 4[ ] 20 5 [ ] 075 [1 ] 1 5 20 [1]
) 5 004 ) 5 01 ) 10 01 ) 15 02
pA B C A C kg m I kg m s s a a a
a Q b Q c Q d Q
(a) (b)
(c) (d)
II The spider-type systems motion 24
m r K K K
1 2
3 4
5 6
4 2 m r
Ap p
Bq J I q I
Cr r
K K
ed
dt
Kω K M
12 56 34
34 12 56
56 34 12
ex
ey
ez
Ap I C B qr I q r M
Bq I A C pr I r p M
Cr I B A pq I p q M
4 2
4 2 4 2
iji j A A J I
B B J I C C J I
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i ex x
i e i ey y
i e i ez z
I p M M I p M M
I q M M I q M M
I r M M I r M M
(1)
(2)
(3)
(4)
II1 Angular momentum of the system in projections onto axes of the frame Oxyz
II2 The motion equations of the multirotor system
25
1 1
1 1
4 2
4 2 4 2
N Nij
il jl ll l
N N
l ll l
A A J NI
B B J NI C C J NI
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i el l lx l l lx
i e i el l ly l l ly
i e i el l lz l l lz
I p M M I p M M
I q M M I q M M
I r M M I r M M
0
1
2
3
cos 2
cos sin2
cos sin2
cos sin2
2 λ Θ λ
0
1
2
3
0
0
0
0
p q r
p r q
q r p
r q p
λ Θ
(4rsquo)
II3 The Euler parameters
(5)
26II4 The conjugate spinups and captures
Def1 Conjugate rotors are paired rotors located in the same layer on the opposite rays For example rotor 3N and rotor 4N are conjugate rotors (also rotor 12 and rotor 22 etc)
Def2 Conjugate spinup mean a process of spinning up conjugate rotors in opposite directions up to a desired value of relative angular velocity with the help of internal moments from main body Velocities of conjugate rotors will be equal in absolute value and opposite in sign
Def3 Rotor capture is an immediate deceleration of rotor relative angular velocity with the help of internal moment from the main body So rotor capture means an ldquoinstantaneous freezingrdquo of rotor with respect to the main body The capture can be performed with the help of gear meshing friction clutch or other methods
27
(6)
II6 Analytical solutions of motion equations
0e e ex y zM M M
A B C D
12 121
12 122
0
0
0
0
si
si
M if t tM
otherwise
M if t tM
otherwise
12 12 12sS M t I
1 12 2 12S S
1 1 12c c st t t
1 0
12
122
ISp
A IAS
A I
1 0 Conjugate spinup of rotors 1 2
Rotor 1 capture
Rotor 2 capture
2 2 1c c ct t t
1 2
121 2
0 0
c c
c c
t t tp IS
P t t tA I
Two serial captures of conjugate rotors bring to piecewise constant angular velocity of the main body
The main body performed the rotation about Ox axis by finite angle 12 2 1
c c
x
IS t t
A I
28
1 3 5 2 4 6
0 1 2 3
1 0
c c c c c c c cstart finish
c c c cstart start start start
t t t t t t t t
t t t t
0 1
2 3
2 2 2
cos sin2 2
sin sin2 2
c cstart start
c cstart start
c c c cstart finish finish start
t t t tPt t
t t t tQ Rt t
P Q R t t t T t t
1 2 t t t p P q Q r R
Letrsquos assume synchronically captures of coresponded conjugate rotors 1 2 3 4 5 6 and coincidence of the frame Oxyz initial position and the fixed frame OXYZ
Angular velocities between conjugate captures of rotors
Solutions of kinematic equations (5)
cos cos cosT
P Q R
T
e
The main body performed finite rotation about vector e by angle χ
(18)
(20)
(19)
(21)
29II7 Numerical simulation of reorientation process
const 0 1 135 246
i s cj jj j j
i s cj jj j j
jj
M M H t H t t H t t
M M H t H t t H t t
M j j
Two sets of results of numerical simulation
1 4 5(0) (0) (0) 0 (0) 100 1 s ω
ν = 300 Nms
H(t) is Heaviside function
FigA - zero value of angular momentum and different inertia moments of main body
Fig A Fig B
Fig4 - reorientation process at nonzero system angular momentum
30
__________________________________________________________
The main properties of the attitude stabilization and control of SC (and multirotor systems) have been examined
Research into attitude motion of the one-body-SC dual-spin SC and spider-type-SC is very complicated
Nontrivial and chaotic modes are possible in the SC attitude motion
Conclusion
- Slide 1
- Outline
- Part 1 - Introduction to Attitude Dynamics and Control
- Slide 4
- Spin stabilization
- Spin Stabilization Dual-Spin Spacecraft
- Spin Stabilization Dual-Spin Spacecraft (2)
- Spin Stabilization Dual-Spin Spacecraft (3)
- Spin Stabilization Dual-Spin Spacecraft (4)
- Gravity Gradient Stabilization
- Magnetic Stabilization
- Aerodynamic Stabilization
- Actuators
- Actuators (2)
- Actuators (3)
- Main Equations of Angular Motion of Rigid Body (Attitude Motion
- Main Properties of the Free Angular Motion of Rigid Body (Attit
- Main Properties of the Free Angular Motion of Rigid Body (Attit (2)
- Part 2 ndash Research Results
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
-
1cos sin
cos
sin cos
sincos sin
cos
p q
p q
r p q
(1)
(2)
15
I1 The angular motion general equations
I The coaxial bodies system motion
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
cos sinP
P Q M Q
The coaxial top
I2 The angular motion equations of the magnetic DSSC and the coaxial Lagrange top
16
The single dipole model of the Earthrsquos magnetic field and the constant magnetic field vector corresponding to the circle equatorial orbit
The magnetic DSSC coordinate frames
17I3 The equations
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
2 2 2
2 1
0
T
x y zOx y z
T
orb orb
M M M
B m B m
oθ
θ
rbM m B
M
1 2
2 2
3 2
cos
cos
cos
OZ Ox
OZ Oy
OZ Oz
i k
j k
k k
2 2
2 1
2
0
Ap C B qr q Q
Bq A C pr p Q
C r B A pq M
orbQ B m
1
22 2 2 2 22
1 2 1 2 1 2
sin cos 1
2 2
T P
LI L l lT
A A A B C C
H H
cos sinP
P Q M Q
(6)
(5)
(4)
(3)
(2)
(1)
18I4 The integrals and solutions
2
2
2
1
2
23
x
y
z
K Ap
K KK Bq
K KK C r
K K
2
2
2
2 3
2
const
cos
z
z
L K C r
I I K
K C rL
K K K
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
2
2 2 22 2
1
2 2Ap Bq C r E C r TC
22 2 2 2 22 2A p B q C r K DT
2 1 2
22 21
2
22 2
Bq A C f q f q
C B C Ff q V E
A A B A A B
H B A B qf q V V
C A C
- AV Doroshin Exact Solutions in Attitude Dynamics of a Magnetic Dual-Spin Spacecraft and a Generalization of the Lagrange Top WSEAS Transactions on Systems Issue 10 Volume 12 (2013)
471-482
(11) (10)
(9)
(8) (7)
19I5 The analytical solution
The polhodes ellipsoid
2
2 2
22 2
2 1
1
1
q t H C A C x t SB A B
p t C B C x t FA A B
EAr t x t S t r t
A C C
2 20 0
2 20 0
sn
sn
i
i
R P c N t t I kx t e
R P c N t t I k
S E
The numerical integration (lines) and analytical (points) results
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075 q0=2 r0=583 [1s] K=50
[kgm2s] Q=100 [kgm2s2]
5
(13)
(12)
20I6 The analytical solution for Euler angles
orbB
K2K + ω timesK = mtimesK
K + ΩtimesK = 0
orbB
K 2Ω ω m
γ + Ωtimes γ = 0
1
2
3 2
t Ap t K
t Bq t K
C r t K
2cos
tg
t C r t K
Ap tt
Bq t
0
0
2 2
0 2 2 2 2
01
( ) ( )
( ) ( )
( )
t
t
t
t
Ap t Bq tt K dt
A p t B q t
t r t dtC
5
10 20 3003 052 08
The numerical integration (lines) and analytical (points) results for the directional cosines
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075
q0=2 r0=583 [1s] K=50 [km2s]
Q=100 [kgm2s2]
(19)
(20)
(18) (17)
(16)
(15)
(14)
21I7 Hamilton form of equations in the Andoyer-Deprit variables
(21)
(25)
(22)
(23)
(24)
1 C r
22
3 23
T T
T
L I Kl
I L I
K k K s K
K k
2
2
2
2 22
2 22
2
sin
cos
x
y
z
K Ap I L l
K Bq I L l
K C r L
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
22 2 2 2 22
1 2 1 2 1 2 2
sin cos 1
2 2
LI L l l LQ
A A A B C C I
H
22
(26)
Hamilton form of equations 2 2 2 1 1A B C A C
Equations (21) have heteroclinic solutions
Perturbations
0 0 L lM t f l t L t g t t dt
Melnikov function
(28)
The Melnikov function has the infinite number of simple roots This proves the fact of the motion chaotization at the presence of small harmonic perturbations
22 2 2 2
2 1
C B C EB
p t y t q t s k y t E r t y t t r tA A B B C C
0
sin cosN
n p n pn
Q t a n t b n t
22 2 2 2 2
20 0
1 2 1 2 1 2 2 20 1 0 1
sin cos 1
2 2
LI L l l L LQ Q Q t
A A A B C C I I
H H H H H
0 0 1 1
L L
L l L l
l l
L f l L gf f g g
l L l Ll f l L g
H H H H
0 0 00
cos sinN
ns n p n p
n
M t J a n t b n t
(27)
(26)
00 0 2
2
00 1 2 02
4 exp
exp 4
M aa E y t
ky t
Mt aE y a a a
k
23
2 l L I
I8 Numerical modeling Poincareacute sections mod 2 0pt
2 22 2 2 1 1 2 1 3 5
0 0 0 0
15 10 6 5 4[ ] 20 5 [ ] 075 [1 ] 1 5 20 [1]
) 5 004 ) 5 01 ) 10 01 ) 15 02
pA B C A C kg m I kg m s s a a a
a Q b Q c Q d Q
(a) (b)
(c) (d)
II The spider-type systems motion 24
m r K K K
1 2
3 4
5 6
4 2 m r
Ap p
Bq J I q I
Cr r
K K
ed
dt
Kω K M
12 56 34
34 12 56
56 34 12
ex
ey
ez
Ap I C B qr I q r M
Bq I A C pr I r p M
Cr I B A pq I p q M
4 2
4 2 4 2
iji j A A J I
B B J I C C J I
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i ex x
i e i ey y
i e i ez z
I p M M I p M M
I q M M I q M M
I r M M I r M M
(1)
(2)
(3)
(4)
II1 Angular momentum of the system in projections onto axes of the frame Oxyz
II2 The motion equations of the multirotor system
25
1 1
1 1
4 2
4 2 4 2
N Nij
il jl ll l
N N
l ll l
A A J NI
B B J NI C C J NI
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i el l lx l l lx
i e i el l ly l l ly
i e i el l lz l l lz
I p M M I p M M
I q M M I q M M
I r M M I r M M
0
1
2
3
cos 2
cos sin2
cos sin2
cos sin2
2 λ Θ λ
0
1
2
3
0
0
0
0
p q r
p r q
q r p
r q p
λ Θ
(4rsquo)
II3 The Euler parameters
(5)
26II4 The conjugate spinups and captures
Def1 Conjugate rotors are paired rotors located in the same layer on the opposite rays For example rotor 3N and rotor 4N are conjugate rotors (also rotor 12 and rotor 22 etc)
Def2 Conjugate spinup mean a process of spinning up conjugate rotors in opposite directions up to a desired value of relative angular velocity with the help of internal moments from main body Velocities of conjugate rotors will be equal in absolute value and opposite in sign
Def3 Rotor capture is an immediate deceleration of rotor relative angular velocity with the help of internal moment from the main body So rotor capture means an ldquoinstantaneous freezingrdquo of rotor with respect to the main body The capture can be performed with the help of gear meshing friction clutch or other methods
27
(6)
II6 Analytical solutions of motion equations
0e e ex y zM M M
A B C D
12 121
12 122
0
0
0
0
si
si
M if t tM
otherwise
M if t tM
otherwise
12 12 12sS M t I
1 12 2 12S S
1 1 12c c st t t
1 0
12
122
ISp
A IAS
A I
1 0 Conjugate spinup of rotors 1 2
Rotor 1 capture
Rotor 2 capture
2 2 1c c ct t t
1 2
121 2
0 0
c c
c c
t t tp IS
P t t tA I
Two serial captures of conjugate rotors bring to piecewise constant angular velocity of the main body
The main body performed the rotation about Ox axis by finite angle 12 2 1
c c
x
IS t t
A I
28
1 3 5 2 4 6
0 1 2 3
1 0
c c c c c c c cstart finish
c c c cstart start start start
t t t t t t t t
t t t t
0 1
2 3
2 2 2
cos sin2 2
sin sin2 2
c cstart start
c cstart start
c c c cstart finish finish start
t t t tPt t
t t t tQ Rt t
P Q R t t t T t t
1 2 t t t p P q Q r R
Letrsquos assume synchronically captures of coresponded conjugate rotors 1 2 3 4 5 6 and coincidence of the frame Oxyz initial position and the fixed frame OXYZ
Angular velocities between conjugate captures of rotors
Solutions of kinematic equations (5)
cos cos cosT
P Q R
T
e
The main body performed finite rotation about vector e by angle χ
(18)
(20)
(19)
(21)
29II7 Numerical simulation of reorientation process
const 0 1 135 246
i s cj jj j j
i s cj jj j j
jj
M M H t H t t H t t
M M H t H t t H t t
M j j
Two sets of results of numerical simulation
1 4 5(0) (0) (0) 0 (0) 100 1 s ω
ν = 300 Nms
H(t) is Heaviside function
FigA - zero value of angular momentum and different inertia moments of main body
Fig A Fig B
Fig4 - reorientation process at nonzero system angular momentum
30
__________________________________________________________
The main properties of the attitude stabilization and control of SC (and multirotor systems) have been examined
Research into attitude motion of the one-body-SC dual-spin SC and spider-type-SC is very complicated
Nontrivial and chaotic modes are possible in the SC attitude motion
Conclusion
- Slide 1
- Outline
- Part 1 - Introduction to Attitude Dynamics and Control
- Slide 4
- Spin stabilization
- Spin Stabilization Dual-Spin Spacecraft
- Spin Stabilization Dual-Spin Spacecraft (2)
- Spin Stabilization Dual-Spin Spacecraft (3)
- Spin Stabilization Dual-Spin Spacecraft (4)
- Gravity Gradient Stabilization
- Magnetic Stabilization
- Aerodynamic Stabilization
- Actuators
- Actuators (2)
- Actuators (3)
- Main Equations of Angular Motion of Rigid Body (Attitude Motion
- Main Properties of the Free Angular Motion of Rigid Body (Attit
- Main Properties of the Free Angular Motion of Rigid Body (Attit (2)
- Part 2 ndash Research Results
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
-
I2 The angular motion equations of the magnetic DSSC and the coaxial Lagrange top
16
The single dipole model of the Earthrsquos magnetic field and the constant magnetic field vector corresponding to the circle equatorial orbit
The magnetic DSSC coordinate frames
17I3 The equations
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
2 2 2
2 1
0
T
x y zOx y z
T
orb orb
M M M
B m B m
oθ
θ
rbM m B
M
1 2
2 2
3 2
cos
cos
cos
OZ Ox
OZ Oy
OZ Oz
i k
j k
k k
2 2
2 1
2
0
Ap C B qr q Q
Bq A C pr p Q
C r B A pq M
orbQ B m
1
22 2 2 2 22
1 2 1 2 1 2
sin cos 1
2 2
T P
LI L l lT
A A A B C C
H H
cos sinP
P Q M Q
(6)
(5)
(4)
(3)
(2)
(1)
18I4 The integrals and solutions
2
2
2
1
2
23
x
y
z
K Ap
K KK Bq
K KK C r
K K
2
2
2
2 3
2
const
cos
z
z
L K C r
I I K
K C rL
K K K
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
2
2 2 22 2
1
2 2Ap Bq C r E C r TC
22 2 2 2 22 2A p B q C r K DT
2 1 2
22 21
2
22 2
Bq A C f q f q
C B C Ff q V E
A A B A A B
H B A B qf q V V
C A C
- AV Doroshin Exact Solutions in Attitude Dynamics of a Magnetic Dual-Spin Spacecraft and a Generalization of the Lagrange Top WSEAS Transactions on Systems Issue 10 Volume 12 (2013)
471-482
(11) (10)
(9)
(8) (7)
19I5 The analytical solution
The polhodes ellipsoid
2
2 2
22 2
2 1
1
1
q t H C A C x t SB A B
p t C B C x t FA A B
EAr t x t S t r t
A C C
2 20 0
2 20 0
sn
sn
i
i
R P c N t t I kx t e
R P c N t t I k
S E
The numerical integration (lines) and analytical (points) results
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075 q0=2 r0=583 [1s] K=50
[kgm2s] Q=100 [kgm2s2]
5
(13)
(12)
20I6 The analytical solution for Euler angles
orbB
K2K + ω timesK = mtimesK
K + ΩtimesK = 0
orbB
K 2Ω ω m
γ + Ωtimes γ = 0
1
2
3 2
t Ap t K
t Bq t K
C r t K
2cos
tg
t C r t K
Ap tt
Bq t
0
0
2 2
0 2 2 2 2
01
( ) ( )
( ) ( )
( )
t
t
t
t
Ap t Bq tt K dt
A p t B q t
t r t dtC
5
10 20 3003 052 08
The numerical integration (lines) and analytical (points) results for the directional cosines
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075
q0=2 r0=583 [1s] K=50 [km2s]
Q=100 [kgm2s2]
(19)
(20)
(18) (17)
(16)
(15)
(14)
21I7 Hamilton form of equations in the Andoyer-Deprit variables
(21)
(25)
(22)
(23)
(24)
1 C r
22
3 23
T T
T
L I Kl
I L I
K k K s K
K k
2
2
2
2 22
2 22
2
sin
cos
x
y
z
K Ap I L l
K Bq I L l
K C r L
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
22 2 2 2 22
1 2 1 2 1 2 2
sin cos 1
2 2
LI L l l LQ
A A A B C C I
H
22
(26)
Hamilton form of equations 2 2 2 1 1A B C A C
Equations (21) have heteroclinic solutions
Perturbations
0 0 L lM t f l t L t g t t dt
Melnikov function
(28)
The Melnikov function has the infinite number of simple roots This proves the fact of the motion chaotization at the presence of small harmonic perturbations
22 2 2 2
2 1
C B C EB
p t y t q t s k y t E r t y t t r tA A B B C C
0
sin cosN
n p n pn
Q t a n t b n t
22 2 2 2 2
20 0
1 2 1 2 1 2 2 20 1 0 1
sin cos 1
2 2
LI L l l L LQ Q Q t
A A A B C C I I
H H H H H
0 0 1 1
L L
L l L l
l l
L f l L gf f g g
l L l Ll f l L g
H H H H
0 0 00
cos sinN
ns n p n p
n
M t J a n t b n t
(27)
(26)
00 0 2
2
00 1 2 02
4 exp
exp 4
M aa E y t
ky t
Mt aE y a a a
k
23
2 l L I
I8 Numerical modeling Poincareacute sections mod 2 0pt
2 22 2 2 1 1 2 1 3 5
0 0 0 0
15 10 6 5 4[ ] 20 5 [ ] 075 [1 ] 1 5 20 [1]
) 5 004 ) 5 01 ) 10 01 ) 15 02
pA B C A C kg m I kg m s s a a a
a Q b Q c Q d Q
(a) (b)
(c) (d)
II The spider-type systems motion 24
m r K K K
1 2
3 4
5 6
4 2 m r
Ap p
Bq J I q I
Cr r
K K
ed
dt
Kω K M
12 56 34
34 12 56
56 34 12
ex
ey
ez
Ap I C B qr I q r M
Bq I A C pr I r p M
Cr I B A pq I p q M
4 2
4 2 4 2
iji j A A J I
B B J I C C J I
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i ex x
i e i ey y
i e i ez z
I p M M I p M M
I q M M I q M M
I r M M I r M M
(1)
(2)
(3)
(4)
II1 Angular momentum of the system in projections onto axes of the frame Oxyz
II2 The motion equations of the multirotor system
25
1 1
1 1
4 2
4 2 4 2
N Nij
il jl ll l
N N
l ll l
A A J NI
B B J NI C C J NI
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i el l lx l l lx
i e i el l ly l l ly
i e i el l lz l l lz
I p M M I p M M
I q M M I q M M
I r M M I r M M
0
1
2
3
cos 2
cos sin2
cos sin2
cos sin2
2 λ Θ λ
0
1
2
3
0
0
0
0
p q r
p r q
q r p
r q p
λ Θ
(4rsquo)
II3 The Euler parameters
(5)
26II4 The conjugate spinups and captures
Def1 Conjugate rotors are paired rotors located in the same layer on the opposite rays For example rotor 3N and rotor 4N are conjugate rotors (also rotor 12 and rotor 22 etc)
Def2 Conjugate spinup mean a process of spinning up conjugate rotors in opposite directions up to a desired value of relative angular velocity with the help of internal moments from main body Velocities of conjugate rotors will be equal in absolute value and opposite in sign
Def3 Rotor capture is an immediate deceleration of rotor relative angular velocity with the help of internal moment from the main body So rotor capture means an ldquoinstantaneous freezingrdquo of rotor with respect to the main body The capture can be performed with the help of gear meshing friction clutch or other methods
27
(6)
II6 Analytical solutions of motion equations
0e e ex y zM M M
A B C D
12 121
12 122
0
0
0
0
si
si
M if t tM
otherwise
M if t tM
otherwise
12 12 12sS M t I
1 12 2 12S S
1 1 12c c st t t
1 0
12
122
ISp
A IAS
A I
1 0 Conjugate spinup of rotors 1 2
Rotor 1 capture
Rotor 2 capture
2 2 1c c ct t t
1 2
121 2
0 0
c c
c c
t t tp IS
P t t tA I
Two serial captures of conjugate rotors bring to piecewise constant angular velocity of the main body
The main body performed the rotation about Ox axis by finite angle 12 2 1
c c
x
IS t t
A I
28
1 3 5 2 4 6
0 1 2 3
1 0
c c c c c c c cstart finish
c c c cstart start start start
t t t t t t t t
t t t t
0 1
2 3
2 2 2
cos sin2 2
sin sin2 2
c cstart start
c cstart start
c c c cstart finish finish start
t t t tPt t
t t t tQ Rt t
P Q R t t t T t t
1 2 t t t p P q Q r R
Letrsquos assume synchronically captures of coresponded conjugate rotors 1 2 3 4 5 6 and coincidence of the frame Oxyz initial position and the fixed frame OXYZ
Angular velocities between conjugate captures of rotors
Solutions of kinematic equations (5)
cos cos cosT
P Q R
T
e
The main body performed finite rotation about vector e by angle χ
(18)
(20)
(19)
(21)
29II7 Numerical simulation of reorientation process
const 0 1 135 246
i s cj jj j j
i s cj jj j j
jj
M M H t H t t H t t
M M H t H t t H t t
M j j
Two sets of results of numerical simulation
1 4 5(0) (0) (0) 0 (0) 100 1 s ω
ν = 300 Nms
H(t) is Heaviside function
FigA - zero value of angular momentum and different inertia moments of main body
Fig A Fig B
Fig4 - reorientation process at nonzero system angular momentum
30
__________________________________________________________
The main properties of the attitude stabilization and control of SC (and multirotor systems) have been examined
Research into attitude motion of the one-body-SC dual-spin SC and spider-type-SC is very complicated
Nontrivial and chaotic modes are possible in the SC attitude motion
Conclusion
- Slide 1
- Outline
- Part 1 - Introduction to Attitude Dynamics and Control
- Slide 4
- Spin stabilization
- Spin Stabilization Dual-Spin Spacecraft
- Spin Stabilization Dual-Spin Spacecraft (2)
- Spin Stabilization Dual-Spin Spacecraft (3)
- Spin Stabilization Dual-Spin Spacecraft (4)
- Gravity Gradient Stabilization
- Magnetic Stabilization
- Aerodynamic Stabilization
- Actuators
- Actuators (2)
- Actuators (3)
- Main Equations of Angular Motion of Rigid Body (Attitude Motion
- Main Properties of the Free Angular Motion of Rigid Body (Attit
- Main Properties of the Free Angular Motion of Rigid Body (Attit (2)
- Part 2 ndash Research Results
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
-
17I3 The equations
1
1
1
1
x
y
z
Ap C B qr qC M
Bq A C pr pC M
Cr C B A pq M
C r M
2 2 2
2 1
0
T
x y zOx y z
T
orb orb
M M M
B m B m
oθ
θ
rbM m B
M
1 2
2 2
3 2
cos
cos
cos
OZ Ox
OZ Oy
OZ Oz
i k
j k
k k
2 2
2 1
2
0
Ap C B qr q Q
Bq A C pr p Q
C r B A pq M
orbQ B m
1
22 2 2 2 22
1 2 1 2 1 2
sin cos 1
2 2
T P
LI L l lT
A A A B C C
H H
cos sinP
P Q M Q
(6)
(5)
(4)
(3)
(2)
(1)
18I4 The integrals and solutions
2
2
2
1
2
23
x
y
z
K Ap
K KK Bq
K KK C r
K K
2
2
2
2 3
2
const
cos
z
z
L K C r
I I K
K C rL
K K K
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
2
2 2 22 2
1
2 2Ap Bq C r E C r TC
22 2 2 2 22 2A p B q C r K DT
2 1 2
22 21
2
22 2
Bq A C f q f q
C B C Ff q V E
A A B A A B
H B A B qf q V V
C A C
- AV Doroshin Exact Solutions in Attitude Dynamics of a Magnetic Dual-Spin Spacecraft and a Generalization of the Lagrange Top WSEAS Transactions on Systems Issue 10 Volume 12 (2013)
471-482
(11) (10)
(9)
(8) (7)
19I5 The analytical solution
The polhodes ellipsoid
2
2 2
22 2
2 1
1
1
q t H C A C x t SB A B
p t C B C x t FA A B
EAr t x t S t r t
A C C
2 20 0
2 20 0
sn
sn
i
i
R P c N t t I kx t e
R P c N t t I k
S E
The numerical integration (lines) and analytical (points) results
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075 q0=2 r0=583 [1s] K=50
[kgm2s] Q=100 [kgm2s2]
5
(13)
(12)
20I6 The analytical solution for Euler angles
orbB
K2K + ω timesK = mtimesK
K + ΩtimesK = 0
orbB
K 2Ω ω m
γ + Ωtimes γ = 0
1
2
3 2
t Ap t K
t Bq t K
C r t K
2cos
tg
t C r t K
Ap tt
Bq t
0
0
2 2
0 2 2 2 2
01
( ) ( )
( ) ( )
( )
t
t
t
t
Ap t Bq tt K dt
A p t B q t
t r t dtC
5
10 20 3003 052 08
The numerical integration (lines) and analytical (points) results for the directional cosines
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075
q0=2 r0=583 [1s] K=50 [km2s]
Q=100 [kgm2s2]
(19)
(20)
(18) (17)
(16)
(15)
(14)
21I7 Hamilton form of equations in the Andoyer-Deprit variables
(21)
(25)
(22)
(23)
(24)
1 C r
22
3 23
T T
T
L I Kl
I L I
K k K s K
K k
2
2
2
2 22
2 22
2
sin
cos
x
y
z
K Ap I L l
K Bq I L l
K C r L
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
22 2 2 2 22
1 2 1 2 1 2 2
sin cos 1
2 2
LI L l l LQ
A A A B C C I
H
22
(26)
Hamilton form of equations 2 2 2 1 1A B C A C
Equations (21) have heteroclinic solutions
Perturbations
0 0 L lM t f l t L t g t t dt
Melnikov function
(28)
The Melnikov function has the infinite number of simple roots This proves the fact of the motion chaotization at the presence of small harmonic perturbations
22 2 2 2
2 1
C B C EB
p t y t q t s k y t E r t y t t r tA A B B C C
0
sin cosN
n p n pn
Q t a n t b n t
22 2 2 2 2
20 0
1 2 1 2 1 2 2 20 1 0 1
sin cos 1
2 2
LI L l l L LQ Q Q t
A A A B C C I I
H H H H H
0 0 1 1
L L
L l L l
l l
L f l L gf f g g
l L l Ll f l L g
H H H H
0 0 00
cos sinN
ns n p n p
n
M t J a n t b n t
(27)
(26)
00 0 2
2
00 1 2 02
4 exp
exp 4
M aa E y t
ky t
Mt aE y a a a
k
23
2 l L I
I8 Numerical modeling Poincareacute sections mod 2 0pt
2 22 2 2 1 1 2 1 3 5
0 0 0 0
15 10 6 5 4[ ] 20 5 [ ] 075 [1 ] 1 5 20 [1]
) 5 004 ) 5 01 ) 10 01 ) 15 02
pA B C A C kg m I kg m s s a a a
a Q b Q c Q d Q
(a) (b)
(c) (d)
II The spider-type systems motion 24
m r K K K
1 2
3 4
5 6
4 2 m r
Ap p
Bq J I q I
Cr r
K K
ed
dt
Kω K M
12 56 34
34 12 56
56 34 12
ex
ey
ez
Ap I C B qr I q r M
Bq I A C pr I r p M
Cr I B A pq I p q M
4 2
4 2 4 2
iji j A A J I
B B J I C C J I
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i ex x
i e i ey y
i e i ez z
I p M M I p M M
I q M M I q M M
I r M M I r M M
(1)
(2)
(3)
(4)
II1 Angular momentum of the system in projections onto axes of the frame Oxyz
II2 The motion equations of the multirotor system
25
1 1
1 1
4 2
4 2 4 2
N Nij
il jl ll l
N N
l ll l
A A J NI
B B J NI C C J NI
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i el l lx l l lx
i e i el l ly l l ly
i e i el l lz l l lz
I p M M I p M M
I q M M I q M M
I r M M I r M M
0
1
2
3
cos 2
cos sin2
cos sin2
cos sin2
2 λ Θ λ
0
1
2
3
0
0
0
0
p q r
p r q
q r p
r q p
λ Θ
(4rsquo)
II3 The Euler parameters
(5)
26II4 The conjugate spinups and captures
Def1 Conjugate rotors are paired rotors located in the same layer on the opposite rays For example rotor 3N and rotor 4N are conjugate rotors (also rotor 12 and rotor 22 etc)
Def2 Conjugate spinup mean a process of spinning up conjugate rotors in opposite directions up to a desired value of relative angular velocity with the help of internal moments from main body Velocities of conjugate rotors will be equal in absolute value and opposite in sign
Def3 Rotor capture is an immediate deceleration of rotor relative angular velocity with the help of internal moment from the main body So rotor capture means an ldquoinstantaneous freezingrdquo of rotor with respect to the main body The capture can be performed with the help of gear meshing friction clutch or other methods
27
(6)
II6 Analytical solutions of motion equations
0e e ex y zM M M
A B C D
12 121
12 122
0
0
0
0
si
si
M if t tM
otherwise
M if t tM
otherwise
12 12 12sS M t I
1 12 2 12S S
1 1 12c c st t t
1 0
12
122
ISp
A IAS
A I
1 0 Conjugate spinup of rotors 1 2
Rotor 1 capture
Rotor 2 capture
2 2 1c c ct t t
1 2
121 2
0 0
c c
c c
t t tp IS
P t t tA I
Two serial captures of conjugate rotors bring to piecewise constant angular velocity of the main body
The main body performed the rotation about Ox axis by finite angle 12 2 1
c c
x
IS t t
A I
28
1 3 5 2 4 6
0 1 2 3
1 0
c c c c c c c cstart finish
c c c cstart start start start
t t t t t t t t
t t t t
0 1
2 3
2 2 2
cos sin2 2
sin sin2 2
c cstart start
c cstart start
c c c cstart finish finish start
t t t tPt t
t t t tQ Rt t
P Q R t t t T t t
1 2 t t t p P q Q r R
Letrsquos assume synchronically captures of coresponded conjugate rotors 1 2 3 4 5 6 and coincidence of the frame Oxyz initial position and the fixed frame OXYZ
Angular velocities between conjugate captures of rotors
Solutions of kinematic equations (5)
cos cos cosT
P Q R
T
e
The main body performed finite rotation about vector e by angle χ
(18)
(20)
(19)
(21)
29II7 Numerical simulation of reorientation process
const 0 1 135 246
i s cj jj j j
i s cj jj j j
jj
M M H t H t t H t t
M M H t H t t H t t
M j j
Two sets of results of numerical simulation
1 4 5(0) (0) (0) 0 (0) 100 1 s ω
ν = 300 Nms
H(t) is Heaviside function
FigA - zero value of angular momentum and different inertia moments of main body
Fig A Fig B
Fig4 - reorientation process at nonzero system angular momentum
30
__________________________________________________________
The main properties of the attitude stabilization and control of SC (and multirotor systems) have been examined
Research into attitude motion of the one-body-SC dual-spin SC and spider-type-SC is very complicated
Nontrivial and chaotic modes are possible in the SC attitude motion
Conclusion
- Slide 1
- Outline
- Part 1 - Introduction to Attitude Dynamics and Control
- Slide 4
- Spin stabilization
- Spin Stabilization Dual-Spin Spacecraft
- Spin Stabilization Dual-Spin Spacecraft (2)
- Spin Stabilization Dual-Spin Spacecraft (3)
- Spin Stabilization Dual-Spin Spacecraft (4)
- Gravity Gradient Stabilization
- Magnetic Stabilization
- Aerodynamic Stabilization
- Actuators
- Actuators (2)
- Actuators (3)
- Main Equations of Angular Motion of Rigid Body (Attitude Motion
- Main Properties of the Free Angular Motion of Rigid Body (Attit
- Main Properties of the Free Angular Motion of Rigid Body (Attit (2)
- Part 2 ndash Research Results
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
-
18I4 The integrals and solutions
2
2
2
1
2
23
x
y
z
K Ap
K KK Bq
K KK C r
K K
2
2
2
2 3
2
const
cos
z
z
L K C r
I I K
K C rL
K K K
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
2
2 2 22 2
1
2 2Ap Bq C r E C r TC
22 2 2 2 22 2A p B q C r K DT
2 1 2
22 21
2
22 2
Bq A C f q f q
C B C Ff q V E
A A B A A B
H B A B qf q V V
C A C
- AV Doroshin Exact Solutions in Attitude Dynamics of a Magnetic Dual-Spin Spacecraft and a Generalization of the Lagrange Top WSEAS Transactions on Systems Issue 10 Volume 12 (2013)
471-482
(11) (10)
(9)
(8) (7)
19I5 The analytical solution
The polhodes ellipsoid
2
2 2
22 2
2 1
1
1
q t H C A C x t SB A B
p t C B C x t FA A B
EAr t x t S t r t
A C C
2 20 0
2 20 0
sn
sn
i
i
R P c N t t I kx t e
R P c N t t I k
S E
The numerical integration (lines) and analytical (points) results
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075 q0=2 r0=583 [1s] K=50
[kgm2s] Q=100 [kgm2s2]
5
(13)
(12)
20I6 The analytical solution for Euler angles
orbB
K2K + ω timesK = mtimesK
K + ΩtimesK = 0
orbB
K 2Ω ω m
γ + Ωtimes γ = 0
1
2
3 2
t Ap t K
t Bq t K
C r t K
2cos
tg
t C r t K
Ap tt
Bq t
0
0
2 2
0 2 2 2 2
01
( ) ( )
( ) ( )
( )
t
t
t
t
Ap t Bq tt K dt
A p t B q t
t r t dtC
5
10 20 3003 052 08
The numerical integration (lines) and analytical (points) results for the directional cosines
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075
q0=2 r0=583 [1s] K=50 [km2s]
Q=100 [kgm2s2]
(19)
(20)
(18) (17)
(16)
(15)
(14)
21I7 Hamilton form of equations in the Andoyer-Deprit variables
(21)
(25)
(22)
(23)
(24)
1 C r
22
3 23
T T
T
L I Kl
I L I
K k K s K
K k
2
2
2
2 22
2 22
2
sin
cos
x
y
z
K Ap I L l
K Bq I L l
K C r L
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
22 2 2 2 22
1 2 1 2 1 2 2
sin cos 1
2 2
LI L l l LQ
A A A B C C I
H
22
(26)
Hamilton form of equations 2 2 2 1 1A B C A C
Equations (21) have heteroclinic solutions
Perturbations
0 0 L lM t f l t L t g t t dt
Melnikov function
(28)
The Melnikov function has the infinite number of simple roots This proves the fact of the motion chaotization at the presence of small harmonic perturbations
22 2 2 2
2 1
C B C EB
p t y t q t s k y t E r t y t t r tA A B B C C
0
sin cosN
n p n pn
Q t a n t b n t
22 2 2 2 2
20 0
1 2 1 2 1 2 2 20 1 0 1
sin cos 1
2 2
LI L l l L LQ Q Q t
A A A B C C I I
H H H H H
0 0 1 1
L L
L l L l
l l
L f l L gf f g g
l L l Ll f l L g
H H H H
0 0 00
cos sinN
ns n p n p
n
M t J a n t b n t
(27)
(26)
00 0 2
2
00 1 2 02
4 exp
exp 4
M aa E y t
ky t
Mt aE y a a a
k
23
2 l L I
I8 Numerical modeling Poincareacute sections mod 2 0pt
2 22 2 2 1 1 2 1 3 5
0 0 0 0
15 10 6 5 4[ ] 20 5 [ ] 075 [1 ] 1 5 20 [1]
) 5 004 ) 5 01 ) 10 01 ) 15 02
pA B C A C kg m I kg m s s a a a
a Q b Q c Q d Q
(a) (b)
(c) (d)
II The spider-type systems motion 24
m r K K K
1 2
3 4
5 6
4 2 m r
Ap p
Bq J I q I
Cr r
K K
ed
dt
Kω K M
12 56 34
34 12 56
56 34 12
ex
ey
ez
Ap I C B qr I q r M
Bq I A C pr I r p M
Cr I B A pq I p q M
4 2
4 2 4 2
iji j A A J I
B B J I C C J I
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i ex x
i e i ey y
i e i ez z
I p M M I p M M
I q M M I q M M
I r M M I r M M
(1)
(2)
(3)
(4)
II1 Angular momentum of the system in projections onto axes of the frame Oxyz
II2 The motion equations of the multirotor system
25
1 1
1 1
4 2
4 2 4 2
N Nij
il jl ll l
N N
l ll l
A A J NI
B B J NI C C J NI
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i el l lx l l lx
i e i el l ly l l ly
i e i el l lz l l lz
I p M M I p M M
I q M M I q M M
I r M M I r M M
0
1
2
3
cos 2
cos sin2
cos sin2
cos sin2
2 λ Θ λ
0
1
2
3
0
0
0
0
p q r
p r q
q r p
r q p
λ Θ
(4rsquo)
II3 The Euler parameters
(5)
26II4 The conjugate spinups and captures
Def1 Conjugate rotors are paired rotors located in the same layer on the opposite rays For example rotor 3N and rotor 4N are conjugate rotors (also rotor 12 and rotor 22 etc)
Def2 Conjugate spinup mean a process of spinning up conjugate rotors in opposite directions up to a desired value of relative angular velocity with the help of internal moments from main body Velocities of conjugate rotors will be equal in absolute value and opposite in sign
Def3 Rotor capture is an immediate deceleration of rotor relative angular velocity with the help of internal moment from the main body So rotor capture means an ldquoinstantaneous freezingrdquo of rotor with respect to the main body The capture can be performed with the help of gear meshing friction clutch or other methods
27
(6)
II6 Analytical solutions of motion equations
0e e ex y zM M M
A B C D
12 121
12 122
0
0
0
0
si
si
M if t tM
otherwise
M if t tM
otherwise
12 12 12sS M t I
1 12 2 12S S
1 1 12c c st t t
1 0
12
122
ISp
A IAS
A I
1 0 Conjugate spinup of rotors 1 2
Rotor 1 capture
Rotor 2 capture
2 2 1c c ct t t
1 2
121 2
0 0
c c
c c
t t tp IS
P t t tA I
Two serial captures of conjugate rotors bring to piecewise constant angular velocity of the main body
The main body performed the rotation about Ox axis by finite angle 12 2 1
c c
x
IS t t
A I
28
1 3 5 2 4 6
0 1 2 3
1 0
c c c c c c c cstart finish
c c c cstart start start start
t t t t t t t t
t t t t
0 1
2 3
2 2 2
cos sin2 2
sin sin2 2
c cstart start
c cstart start
c c c cstart finish finish start
t t t tPt t
t t t tQ Rt t
P Q R t t t T t t
1 2 t t t p P q Q r R
Letrsquos assume synchronically captures of coresponded conjugate rotors 1 2 3 4 5 6 and coincidence of the frame Oxyz initial position and the fixed frame OXYZ
Angular velocities between conjugate captures of rotors
Solutions of kinematic equations (5)
cos cos cosT
P Q R
T
e
The main body performed finite rotation about vector e by angle χ
(18)
(20)
(19)
(21)
29II7 Numerical simulation of reorientation process
const 0 1 135 246
i s cj jj j j
i s cj jj j j
jj
M M H t H t t H t t
M M H t H t t H t t
M j j
Two sets of results of numerical simulation
1 4 5(0) (0) (0) 0 (0) 100 1 s ω
ν = 300 Nms
H(t) is Heaviside function
FigA - zero value of angular momentum and different inertia moments of main body
Fig A Fig B
Fig4 - reorientation process at nonzero system angular momentum
30
__________________________________________________________
The main properties of the attitude stabilization and control of SC (and multirotor systems) have been examined
Research into attitude motion of the one-body-SC dual-spin SC and spider-type-SC is very complicated
Nontrivial and chaotic modes are possible in the SC attitude motion
Conclusion
- Slide 1
- Outline
- Part 1 - Introduction to Attitude Dynamics and Control
- Slide 4
- Spin stabilization
- Spin Stabilization Dual-Spin Spacecraft
- Spin Stabilization Dual-Spin Spacecraft (2)
- Spin Stabilization Dual-Spin Spacecraft (3)
- Spin Stabilization Dual-Spin Spacecraft (4)
- Gravity Gradient Stabilization
- Magnetic Stabilization
- Aerodynamic Stabilization
- Actuators
- Actuators (2)
- Actuators (3)
- Main Equations of Angular Motion of Rigid Body (Attitude Motion
- Main Properties of the Free Angular Motion of Rigid Body (Attit
- Main Properties of the Free Angular Motion of Rigid Body (Attit (2)
- Part 2 ndash Research Results
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
-
19I5 The analytical solution
The polhodes ellipsoid
2
2 2
22 2
2 1
1
1
q t H C A C x t SB A B
p t C B C x t FA A B
EAr t x t S t r t
A C C
2 20 0
2 20 0
sn
sn
i
i
R P c N t t I kx t e
R P c N t t I k
S E
The numerical integration (lines) and analytical (points) results
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075 q0=2 r0=583 [1s] K=50
[kgm2s] Q=100 [kgm2s2]
5
(13)
(12)
20I6 The analytical solution for Euler angles
orbB
K2K + ω timesK = mtimesK
K + ΩtimesK = 0
orbB
K 2Ω ω m
γ + Ωtimes γ = 0
1
2
3 2
t Ap t K
t Bq t K
C r t K
2cos
tg
t C r t K
Ap tt
Bq t
0
0
2 2
0 2 2 2 2
01
( ) ( )
( ) ( )
( )
t
t
t
t
Ap t Bq tt K dt
A p t B q t
t r t dtC
5
10 20 3003 052 08
The numerical integration (lines) and analytical (points) results for the directional cosines
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075
q0=2 r0=583 [1s] K=50 [km2s]
Q=100 [kgm2s2]
(19)
(20)
(18) (17)
(16)
(15)
(14)
21I7 Hamilton form of equations in the Andoyer-Deprit variables
(21)
(25)
(22)
(23)
(24)
1 C r
22
3 23
T T
T
L I Kl
I L I
K k K s K
K k
2
2
2
2 22
2 22
2
sin
cos
x
y
z
K Ap I L l
K Bq I L l
K C r L
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
22 2 2 2 22
1 2 1 2 1 2 2
sin cos 1
2 2
LI L l l LQ
A A A B C C I
H
22
(26)
Hamilton form of equations 2 2 2 1 1A B C A C
Equations (21) have heteroclinic solutions
Perturbations
0 0 L lM t f l t L t g t t dt
Melnikov function
(28)
The Melnikov function has the infinite number of simple roots This proves the fact of the motion chaotization at the presence of small harmonic perturbations
22 2 2 2
2 1
C B C EB
p t y t q t s k y t E r t y t t r tA A B B C C
0
sin cosN
n p n pn
Q t a n t b n t
22 2 2 2 2
20 0
1 2 1 2 1 2 2 20 1 0 1
sin cos 1
2 2
LI L l l L LQ Q Q t
A A A B C C I I
H H H H H
0 0 1 1
L L
L l L l
l l
L f l L gf f g g
l L l Ll f l L g
H H H H
0 0 00
cos sinN
ns n p n p
n
M t J a n t b n t
(27)
(26)
00 0 2
2
00 1 2 02
4 exp
exp 4
M aa E y t
ky t
Mt aE y a a a
k
23
2 l L I
I8 Numerical modeling Poincareacute sections mod 2 0pt
2 22 2 2 1 1 2 1 3 5
0 0 0 0
15 10 6 5 4[ ] 20 5 [ ] 075 [1 ] 1 5 20 [1]
) 5 004 ) 5 01 ) 10 01 ) 15 02
pA B C A C kg m I kg m s s a a a
a Q b Q c Q d Q
(a) (b)
(c) (d)
II The spider-type systems motion 24
m r K K K
1 2
3 4
5 6
4 2 m r
Ap p
Bq J I q I
Cr r
K K
ed
dt
Kω K M
12 56 34
34 12 56
56 34 12
ex
ey
ez
Ap I C B qr I q r M
Bq I A C pr I r p M
Cr I B A pq I p q M
4 2
4 2 4 2
iji j A A J I
B B J I C C J I
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i ex x
i e i ey y
i e i ez z
I p M M I p M M
I q M M I q M M
I r M M I r M M
(1)
(2)
(3)
(4)
II1 Angular momentum of the system in projections onto axes of the frame Oxyz
II2 The motion equations of the multirotor system
25
1 1
1 1
4 2
4 2 4 2
N Nij
il jl ll l
N N
l ll l
A A J NI
B B J NI C C J NI
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i el l lx l l lx
i e i el l ly l l ly
i e i el l lz l l lz
I p M M I p M M
I q M M I q M M
I r M M I r M M
0
1
2
3
cos 2
cos sin2
cos sin2
cos sin2
2 λ Θ λ
0
1
2
3
0
0
0
0
p q r
p r q
q r p
r q p
λ Θ
(4rsquo)
II3 The Euler parameters
(5)
26II4 The conjugate spinups and captures
Def1 Conjugate rotors are paired rotors located in the same layer on the opposite rays For example rotor 3N and rotor 4N are conjugate rotors (also rotor 12 and rotor 22 etc)
Def2 Conjugate spinup mean a process of spinning up conjugate rotors in opposite directions up to a desired value of relative angular velocity with the help of internal moments from main body Velocities of conjugate rotors will be equal in absolute value and opposite in sign
Def3 Rotor capture is an immediate deceleration of rotor relative angular velocity with the help of internal moment from the main body So rotor capture means an ldquoinstantaneous freezingrdquo of rotor with respect to the main body The capture can be performed with the help of gear meshing friction clutch or other methods
27
(6)
II6 Analytical solutions of motion equations
0e e ex y zM M M
A B C D
12 121
12 122
0
0
0
0
si
si
M if t tM
otherwise
M if t tM
otherwise
12 12 12sS M t I
1 12 2 12S S
1 1 12c c st t t
1 0
12
122
ISp
A IAS
A I
1 0 Conjugate spinup of rotors 1 2
Rotor 1 capture
Rotor 2 capture
2 2 1c c ct t t
1 2
121 2
0 0
c c
c c
t t tp IS
P t t tA I
Two serial captures of conjugate rotors bring to piecewise constant angular velocity of the main body
The main body performed the rotation about Ox axis by finite angle 12 2 1
c c
x
IS t t
A I
28
1 3 5 2 4 6
0 1 2 3
1 0
c c c c c c c cstart finish
c c c cstart start start start
t t t t t t t t
t t t t
0 1
2 3
2 2 2
cos sin2 2
sin sin2 2
c cstart start
c cstart start
c c c cstart finish finish start
t t t tPt t
t t t tQ Rt t
P Q R t t t T t t
1 2 t t t p P q Q r R
Letrsquos assume synchronically captures of coresponded conjugate rotors 1 2 3 4 5 6 and coincidence of the frame Oxyz initial position and the fixed frame OXYZ
Angular velocities between conjugate captures of rotors
Solutions of kinematic equations (5)
cos cos cosT
P Q R
T
e
The main body performed finite rotation about vector e by angle χ
(18)
(20)
(19)
(21)
29II7 Numerical simulation of reorientation process
const 0 1 135 246
i s cj jj j j
i s cj jj j j
jj
M M H t H t t H t t
M M H t H t t H t t
M j j
Two sets of results of numerical simulation
1 4 5(0) (0) (0) 0 (0) 100 1 s ω
ν = 300 Nms
H(t) is Heaviside function
FigA - zero value of angular momentum and different inertia moments of main body
Fig A Fig B
Fig4 - reorientation process at nonzero system angular momentum
30
__________________________________________________________
The main properties of the attitude stabilization and control of SC (and multirotor systems) have been examined
Research into attitude motion of the one-body-SC dual-spin SC and spider-type-SC is very complicated
Nontrivial and chaotic modes are possible in the SC attitude motion
Conclusion
- Slide 1
- Outline
- Part 1 - Introduction to Attitude Dynamics and Control
- Slide 4
- Spin stabilization
- Spin Stabilization Dual-Spin Spacecraft
- Spin Stabilization Dual-Spin Spacecraft (2)
- Spin Stabilization Dual-Spin Spacecraft (3)
- Spin Stabilization Dual-Spin Spacecraft (4)
- Gravity Gradient Stabilization
- Magnetic Stabilization
- Aerodynamic Stabilization
- Actuators
- Actuators (2)
- Actuators (3)
- Main Equations of Angular Motion of Rigid Body (Attitude Motion
- Main Properties of the Free Angular Motion of Rigid Body (Attit
- Main Properties of the Free Angular Motion of Rigid Body (Attit (2)
- Part 2 ndash Research Results
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
-
20I6 The analytical solution for Euler angles
orbB
K2K + ω timesK = mtimesK
K + ΩtimesK = 0
orbB
K 2Ω ω m
γ + Ωtimes γ = 0
1
2
3 2
t Ap t K
t Bq t K
C r t K
2cos
tg
t C r t K
Ap tt
Bq t
0
0
2 2
0 2 2 2 2
01
( ) ( )
( ) ( )
( )
t
t
t
t
Ap t Bq tt K dt
A p t B q t
t r t dtC
5
10 20 3003 052 08
The numerical integration (lines) and analytical (points) results for the directional cosines
A2=15 B2=8 C2=6 A1=5 C1=4 [kgm2] p0=075
q0=2 r0=583 [1s] K=50 [km2s]
Q=100 [kgm2s2]
(19)
(20)
(18) (17)
(16)
(15)
(14)
21I7 Hamilton form of equations in the Andoyer-Deprit variables
(21)
(25)
(22)
(23)
(24)
1 C r
22
3 23
T T
T
L I Kl
I L I
K k K s K
K k
2
2
2
2 22
2 22
2
sin
cos
x
y
z
K Ap I L l
K Bq I L l
K C r L
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
22 2 2 2 22
1 2 1 2 1 2 2
sin cos 1
2 2
LI L l l LQ
A A A B C C I
H
22
(26)
Hamilton form of equations 2 2 2 1 1A B C A C
Equations (21) have heteroclinic solutions
Perturbations
0 0 L lM t f l t L t g t t dt
Melnikov function
(28)
The Melnikov function has the infinite number of simple roots This proves the fact of the motion chaotization at the presence of small harmonic perturbations
22 2 2 2
2 1
C B C EB
p t y t q t s k y t E r t y t t r tA A B B C C
0
sin cosN
n p n pn
Q t a n t b n t
22 2 2 2 2
20 0
1 2 1 2 1 2 2 20 1 0 1
sin cos 1
2 2
LI L l l L LQ Q Q t
A A A B C C I I
H H H H H
0 0 1 1
L L
L l L l
l l
L f l L gf f g g
l L l Ll f l L g
H H H H
0 0 00
cos sinN
ns n p n p
n
M t J a n t b n t
(27)
(26)
00 0 2
2
00 1 2 02
4 exp
exp 4
M aa E y t
ky t
Mt aE y a a a
k
23
2 l L I
I8 Numerical modeling Poincareacute sections mod 2 0pt
2 22 2 2 1 1 2 1 3 5
0 0 0 0
15 10 6 5 4[ ] 20 5 [ ] 075 [1 ] 1 5 20 [1]
) 5 004 ) 5 01 ) 10 01 ) 15 02
pA B C A C kg m I kg m s s a a a
a Q b Q c Q d Q
(a) (b)
(c) (d)
II The spider-type systems motion 24
m r K K K
1 2
3 4
5 6
4 2 m r
Ap p
Bq J I q I
Cr r
K K
ed
dt
Kω K M
12 56 34
34 12 56
56 34 12
ex
ey
ez
Ap I C B qr I q r M
Bq I A C pr I r p M
Cr I B A pq I p q M
4 2
4 2 4 2
iji j A A J I
B B J I C C J I
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i ex x
i e i ey y
i e i ez z
I p M M I p M M
I q M M I q M M
I r M M I r M M
(1)
(2)
(3)
(4)
II1 Angular momentum of the system in projections onto axes of the frame Oxyz
II2 The motion equations of the multirotor system
25
1 1
1 1
4 2
4 2 4 2
N Nij
il jl ll l
N N
l ll l
A A J NI
B B J NI C C J NI
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i el l lx l l lx
i e i el l ly l l ly
i e i el l lz l l lz
I p M M I p M M
I q M M I q M M
I r M M I r M M
0
1
2
3
cos 2
cos sin2
cos sin2
cos sin2
2 λ Θ λ
0
1
2
3
0
0
0
0
p q r
p r q
q r p
r q p
λ Θ
(4rsquo)
II3 The Euler parameters
(5)
26II4 The conjugate spinups and captures
Def1 Conjugate rotors are paired rotors located in the same layer on the opposite rays For example rotor 3N and rotor 4N are conjugate rotors (also rotor 12 and rotor 22 etc)
Def2 Conjugate spinup mean a process of spinning up conjugate rotors in opposite directions up to a desired value of relative angular velocity with the help of internal moments from main body Velocities of conjugate rotors will be equal in absolute value and opposite in sign
Def3 Rotor capture is an immediate deceleration of rotor relative angular velocity with the help of internal moment from the main body So rotor capture means an ldquoinstantaneous freezingrdquo of rotor with respect to the main body The capture can be performed with the help of gear meshing friction clutch or other methods
27
(6)
II6 Analytical solutions of motion equations
0e e ex y zM M M
A B C D
12 121
12 122
0
0
0
0
si
si
M if t tM
otherwise
M if t tM
otherwise
12 12 12sS M t I
1 12 2 12S S
1 1 12c c st t t
1 0
12
122
ISp
A IAS
A I
1 0 Conjugate spinup of rotors 1 2
Rotor 1 capture
Rotor 2 capture
2 2 1c c ct t t
1 2
121 2
0 0
c c
c c
t t tp IS
P t t tA I
Two serial captures of conjugate rotors bring to piecewise constant angular velocity of the main body
The main body performed the rotation about Ox axis by finite angle 12 2 1
c c
x
IS t t
A I
28
1 3 5 2 4 6
0 1 2 3
1 0
c c c c c c c cstart finish
c c c cstart start start start
t t t t t t t t
t t t t
0 1
2 3
2 2 2
cos sin2 2
sin sin2 2
c cstart start
c cstart start
c c c cstart finish finish start
t t t tPt t
t t t tQ Rt t
P Q R t t t T t t
1 2 t t t p P q Q r R
Letrsquos assume synchronically captures of coresponded conjugate rotors 1 2 3 4 5 6 and coincidence of the frame Oxyz initial position and the fixed frame OXYZ
Angular velocities between conjugate captures of rotors
Solutions of kinematic equations (5)
cos cos cosT
P Q R
T
e
The main body performed finite rotation about vector e by angle χ
(18)
(20)
(19)
(21)
29II7 Numerical simulation of reorientation process
const 0 1 135 246
i s cj jj j j
i s cj jj j j
jj
M M H t H t t H t t
M M H t H t t H t t
M j j
Two sets of results of numerical simulation
1 4 5(0) (0) (0) 0 (0) 100 1 s ω
ν = 300 Nms
H(t) is Heaviside function
FigA - zero value of angular momentum and different inertia moments of main body
Fig A Fig B
Fig4 - reorientation process at nonzero system angular momentum
30
__________________________________________________________
The main properties of the attitude stabilization and control of SC (and multirotor systems) have been examined
Research into attitude motion of the one-body-SC dual-spin SC and spider-type-SC is very complicated
Nontrivial and chaotic modes are possible in the SC attitude motion
Conclusion
- Slide 1
- Outline
- Part 1 - Introduction to Attitude Dynamics and Control
- Slide 4
- Spin stabilization
- Spin Stabilization Dual-Spin Spacecraft
- Spin Stabilization Dual-Spin Spacecraft (2)
- Spin Stabilization Dual-Spin Spacecraft (3)
- Spin Stabilization Dual-Spin Spacecraft (4)
- Gravity Gradient Stabilization
- Magnetic Stabilization
- Aerodynamic Stabilization
- Actuators
- Actuators (2)
- Actuators (3)
- Main Equations of Angular Motion of Rigid Body (Attitude Motion
- Main Properties of the Free Angular Motion of Rigid Body (Attit
- Main Properties of the Free Angular Motion of Rigid Body (Attit (2)
- Part 2 ndash Research Results
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
-
21I7 Hamilton form of equations in the Andoyer-Deprit variables
(21)
(25)
(22)
(23)
(24)
1 C r
22
3 23
T T
T
L I Kl
I L I
K k K s K
K k
2
2
2
2 22
2 22
2
sin
cos
x
y
z
K Ap I L l
K Bq I L l
K C r L
2
2
2
0
Ap C B qr q QBq K
Bq A C pr p QAp K
C r B A pq M
22 2 2 2 22
1 2 1 2 1 2 2
sin cos 1
2 2
LI L l l LQ
A A A B C C I
H
22
(26)
Hamilton form of equations 2 2 2 1 1A B C A C
Equations (21) have heteroclinic solutions
Perturbations
0 0 L lM t f l t L t g t t dt
Melnikov function
(28)
The Melnikov function has the infinite number of simple roots This proves the fact of the motion chaotization at the presence of small harmonic perturbations
22 2 2 2
2 1
C B C EB
p t y t q t s k y t E r t y t t r tA A B B C C
0
sin cosN
n p n pn
Q t a n t b n t
22 2 2 2 2
20 0
1 2 1 2 1 2 2 20 1 0 1
sin cos 1
2 2
LI L l l L LQ Q Q t
A A A B C C I I
H H H H H
0 0 1 1
L L
L l L l
l l
L f l L gf f g g
l L l Ll f l L g
H H H H
0 0 00
cos sinN
ns n p n p
n
M t J a n t b n t
(27)
(26)
00 0 2
2
00 1 2 02
4 exp
exp 4
M aa E y t
ky t
Mt aE y a a a
k
23
2 l L I
I8 Numerical modeling Poincareacute sections mod 2 0pt
2 22 2 2 1 1 2 1 3 5
0 0 0 0
15 10 6 5 4[ ] 20 5 [ ] 075 [1 ] 1 5 20 [1]
) 5 004 ) 5 01 ) 10 01 ) 15 02
pA B C A C kg m I kg m s s a a a
a Q b Q c Q d Q
(a) (b)
(c) (d)
II The spider-type systems motion 24
m r K K K
1 2
3 4
5 6
4 2 m r
Ap p
Bq J I q I
Cr r
K K
ed
dt
Kω K M
12 56 34
34 12 56
56 34 12
ex
ey
ez
Ap I C B qr I q r M
Bq I A C pr I r p M
Cr I B A pq I p q M
4 2
4 2 4 2
iji j A A J I
B B J I C C J I
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i ex x
i e i ey y
i e i ez z
I p M M I p M M
I q M M I q M M
I r M M I r M M
(1)
(2)
(3)
(4)
II1 Angular momentum of the system in projections onto axes of the frame Oxyz
II2 The motion equations of the multirotor system
25
1 1
1 1
4 2
4 2 4 2
N Nij
il jl ll l
N N
l ll l
A A J NI
B B J NI C C J NI
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i el l lx l l lx
i e i el l ly l l ly
i e i el l lz l l lz
I p M M I p M M
I q M M I q M M
I r M M I r M M
0
1
2
3
cos 2
cos sin2
cos sin2
cos sin2
2 λ Θ λ
0
1
2
3
0
0
0
0
p q r
p r q
q r p
r q p
λ Θ
(4rsquo)
II3 The Euler parameters
(5)
26II4 The conjugate spinups and captures
Def1 Conjugate rotors are paired rotors located in the same layer on the opposite rays For example rotor 3N and rotor 4N are conjugate rotors (also rotor 12 and rotor 22 etc)
Def2 Conjugate spinup mean a process of spinning up conjugate rotors in opposite directions up to a desired value of relative angular velocity with the help of internal moments from main body Velocities of conjugate rotors will be equal in absolute value and opposite in sign
Def3 Rotor capture is an immediate deceleration of rotor relative angular velocity with the help of internal moment from the main body So rotor capture means an ldquoinstantaneous freezingrdquo of rotor with respect to the main body The capture can be performed with the help of gear meshing friction clutch or other methods
27
(6)
II6 Analytical solutions of motion equations
0e e ex y zM M M
A B C D
12 121
12 122
0
0
0
0
si
si
M if t tM
otherwise
M if t tM
otherwise
12 12 12sS M t I
1 12 2 12S S
1 1 12c c st t t
1 0
12
122
ISp
A IAS
A I
1 0 Conjugate spinup of rotors 1 2
Rotor 1 capture
Rotor 2 capture
2 2 1c c ct t t
1 2
121 2
0 0
c c
c c
t t tp IS
P t t tA I
Two serial captures of conjugate rotors bring to piecewise constant angular velocity of the main body
The main body performed the rotation about Ox axis by finite angle 12 2 1
c c
x
IS t t
A I
28
1 3 5 2 4 6
0 1 2 3
1 0
c c c c c c c cstart finish
c c c cstart start start start
t t t t t t t t
t t t t
0 1
2 3
2 2 2
cos sin2 2
sin sin2 2
c cstart start
c cstart start
c c c cstart finish finish start
t t t tPt t
t t t tQ Rt t
P Q R t t t T t t
1 2 t t t p P q Q r R
Letrsquos assume synchronically captures of coresponded conjugate rotors 1 2 3 4 5 6 and coincidence of the frame Oxyz initial position and the fixed frame OXYZ
Angular velocities between conjugate captures of rotors
Solutions of kinematic equations (5)
cos cos cosT
P Q R
T
e
The main body performed finite rotation about vector e by angle χ
(18)
(20)
(19)
(21)
29II7 Numerical simulation of reorientation process
const 0 1 135 246
i s cj jj j j
i s cj jj j j
jj
M M H t H t t H t t
M M H t H t t H t t
M j j
Two sets of results of numerical simulation
1 4 5(0) (0) (0) 0 (0) 100 1 s ω
ν = 300 Nms
H(t) is Heaviside function
FigA - zero value of angular momentum and different inertia moments of main body
Fig A Fig B
Fig4 - reorientation process at nonzero system angular momentum
30
__________________________________________________________
The main properties of the attitude stabilization and control of SC (and multirotor systems) have been examined
Research into attitude motion of the one-body-SC dual-spin SC and spider-type-SC is very complicated
Nontrivial and chaotic modes are possible in the SC attitude motion
Conclusion
- Slide 1
- Outline
- Part 1 - Introduction to Attitude Dynamics and Control
- Slide 4
- Spin stabilization
- Spin Stabilization Dual-Spin Spacecraft
- Spin Stabilization Dual-Spin Spacecraft (2)
- Spin Stabilization Dual-Spin Spacecraft (3)
- Spin Stabilization Dual-Spin Spacecraft (4)
- Gravity Gradient Stabilization
- Magnetic Stabilization
- Aerodynamic Stabilization
- Actuators
- Actuators (2)
- Actuators (3)
- Main Equations of Angular Motion of Rigid Body (Attitude Motion
- Main Properties of the Free Angular Motion of Rigid Body (Attit
- Main Properties of the Free Angular Motion of Rigid Body (Attit (2)
- Part 2 ndash Research Results
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
-
22
(26)
Hamilton form of equations 2 2 2 1 1A B C A C
Equations (21) have heteroclinic solutions
Perturbations
0 0 L lM t f l t L t g t t dt
Melnikov function
(28)
The Melnikov function has the infinite number of simple roots This proves the fact of the motion chaotization at the presence of small harmonic perturbations
22 2 2 2
2 1
C B C EB
p t y t q t s k y t E r t y t t r tA A B B C C
0
sin cosN
n p n pn
Q t a n t b n t
22 2 2 2 2
20 0
1 2 1 2 1 2 2 20 1 0 1
sin cos 1
2 2
LI L l l L LQ Q Q t
A A A B C C I I
H H H H H
0 0 1 1
L L
L l L l
l l
L f l L gf f g g
l L l Ll f l L g
H H H H
0 0 00
cos sinN
ns n p n p
n
M t J a n t b n t
(27)
(26)
00 0 2
2
00 1 2 02
4 exp
exp 4
M aa E y t
ky t
Mt aE y a a a
k
23
2 l L I
I8 Numerical modeling Poincareacute sections mod 2 0pt
2 22 2 2 1 1 2 1 3 5
0 0 0 0
15 10 6 5 4[ ] 20 5 [ ] 075 [1 ] 1 5 20 [1]
) 5 004 ) 5 01 ) 10 01 ) 15 02
pA B C A C kg m I kg m s s a a a
a Q b Q c Q d Q
(a) (b)
(c) (d)
II The spider-type systems motion 24
m r K K K
1 2
3 4
5 6
4 2 m r
Ap p
Bq J I q I
Cr r
K K
ed
dt
Kω K M
12 56 34
34 12 56
56 34 12
ex
ey
ez
Ap I C B qr I q r M
Bq I A C pr I r p M
Cr I B A pq I p q M
4 2
4 2 4 2
iji j A A J I
B B J I C C J I
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i ex x
i e i ey y
i e i ez z
I p M M I p M M
I q M M I q M M
I r M M I r M M
(1)
(2)
(3)
(4)
II1 Angular momentum of the system in projections onto axes of the frame Oxyz
II2 The motion equations of the multirotor system
25
1 1
1 1
4 2
4 2 4 2
N Nij
il jl ll l
N N
l ll l
A A J NI
B B J NI C C J NI
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i el l lx l l lx
i e i el l ly l l ly
i e i el l lz l l lz
I p M M I p M M
I q M M I q M M
I r M M I r M M
0
1
2
3
cos 2
cos sin2
cos sin2
cos sin2
2 λ Θ λ
0
1
2
3
0
0
0
0
p q r
p r q
q r p
r q p
λ Θ
(4rsquo)
II3 The Euler parameters
(5)
26II4 The conjugate spinups and captures
Def1 Conjugate rotors are paired rotors located in the same layer on the opposite rays For example rotor 3N and rotor 4N are conjugate rotors (also rotor 12 and rotor 22 etc)
Def2 Conjugate spinup mean a process of spinning up conjugate rotors in opposite directions up to a desired value of relative angular velocity with the help of internal moments from main body Velocities of conjugate rotors will be equal in absolute value and opposite in sign
Def3 Rotor capture is an immediate deceleration of rotor relative angular velocity with the help of internal moment from the main body So rotor capture means an ldquoinstantaneous freezingrdquo of rotor with respect to the main body The capture can be performed with the help of gear meshing friction clutch or other methods
27
(6)
II6 Analytical solutions of motion equations
0e e ex y zM M M
A B C D
12 121
12 122
0
0
0
0
si
si
M if t tM
otherwise
M if t tM
otherwise
12 12 12sS M t I
1 12 2 12S S
1 1 12c c st t t
1 0
12
122
ISp
A IAS
A I
1 0 Conjugate spinup of rotors 1 2
Rotor 1 capture
Rotor 2 capture
2 2 1c c ct t t
1 2
121 2
0 0
c c
c c
t t tp IS
P t t tA I
Two serial captures of conjugate rotors bring to piecewise constant angular velocity of the main body
The main body performed the rotation about Ox axis by finite angle 12 2 1
c c
x
IS t t
A I
28
1 3 5 2 4 6
0 1 2 3
1 0
c c c c c c c cstart finish
c c c cstart start start start
t t t t t t t t
t t t t
0 1
2 3
2 2 2
cos sin2 2
sin sin2 2
c cstart start
c cstart start
c c c cstart finish finish start
t t t tPt t
t t t tQ Rt t
P Q R t t t T t t
1 2 t t t p P q Q r R
Letrsquos assume synchronically captures of coresponded conjugate rotors 1 2 3 4 5 6 and coincidence of the frame Oxyz initial position and the fixed frame OXYZ
Angular velocities between conjugate captures of rotors
Solutions of kinematic equations (5)
cos cos cosT
P Q R
T
e
The main body performed finite rotation about vector e by angle χ
(18)
(20)
(19)
(21)
29II7 Numerical simulation of reorientation process
const 0 1 135 246
i s cj jj j j
i s cj jj j j
jj
M M H t H t t H t t
M M H t H t t H t t
M j j
Two sets of results of numerical simulation
1 4 5(0) (0) (0) 0 (0) 100 1 s ω
ν = 300 Nms
H(t) is Heaviside function
FigA - zero value of angular momentum and different inertia moments of main body
Fig A Fig B
Fig4 - reorientation process at nonzero system angular momentum
30
__________________________________________________________
The main properties of the attitude stabilization and control of SC (and multirotor systems) have been examined
Research into attitude motion of the one-body-SC dual-spin SC and spider-type-SC is very complicated
Nontrivial and chaotic modes are possible in the SC attitude motion
Conclusion
- Slide 1
- Outline
- Part 1 - Introduction to Attitude Dynamics and Control
- Slide 4
- Spin stabilization
- Spin Stabilization Dual-Spin Spacecraft
- Spin Stabilization Dual-Spin Spacecraft (2)
- Spin Stabilization Dual-Spin Spacecraft (3)
- Spin Stabilization Dual-Spin Spacecraft (4)
- Gravity Gradient Stabilization
- Magnetic Stabilization
- Aerodynamic Stabilization
- Actuators
- Actuators (2)
- Actuators (3)
- Main Equations of Angular Motion of Rigid Body (Attitude Motion
- Main Properties of the Free Angular Motion of Rigid Body (Attit
- Main Properties of the Free Angular Motion of Rigid Body (Attit (2)
- Part 2 ndash Research Results
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
-
23
2 l L I
I8 Numerical modeling Poincareacute sections mod 2 0pt
2 22 2 2 1 1 2 1 3 5
0 0 0 0
15 10 6 5 4[ ] 20 5 [ ] 075 [1 ] 1 5 20 [1]
) 5 004 ) 5 01 ) 10 01 ) 15 02
pA B C A C kg m I kg m s s a a a
a Q b Q c Q d Q
(a) (b)
(c) (d)
II The spider-type systems motion 24
m r K K K
1 2
3 4
5 6
4 2 m r
Ap p
Bq J I q I
Cr r
K K
ed
dt
Kω K M
12 56 34
34 12 56
56 34 12
ex
ey
ez
Ap I C B qr I q r M
Bq I A C pr I r p M
Cr I B A pq I p q M
4 2
4 2 4 2
iji j A A J I
B B J I C C J I
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i ex x
i e i ey y
i e i ez z
I p M M I p M M
I q M M I q M M
I r M M I r M M
(1)
(2)
(3)
(4)
II1 Angular momentum of the system in projections onto axes of the frame Oxyz
II2 The motion equations of the multirotor system
25
1 1
1 1
4 2
4 2 4 2
N Nij
il jl ll l
N N
l ll l
A A J NI
B B J NI C C J NI
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i el l lx l l lx
i e i el l ly l l ly
i e i el l lz l l lz
I p M M I p M M
I q M M I q M M
I r M M I r M M
0
1
2
3
cos 2
cos sin2
cos sin2
cos sin2
2 λ Θ λ
0
1
2
3
0
0
0
0
p q r
p r q
q r p
r q p
λ Θ
(4rsquo)
II3 The Euler parameters
(5)
26II4 The conjugate spinups and captures
Def1 Conjugate rotors are paired rotors located in the same layer on the opposite rays For example rotor 3N and rotor 4N are conjugate rotors (also rotor 12 and rotor 22 etc)
Def2 Conjugate spinup mean a process of spinning up conjugate rotors in opposite directions up to a desired value of relative angular velocity with the help of internal moments from main body Velocities of conjugate rotors will be equal in absolute value and opposite in sign
Def3 Rotor capture is an immediate deceleration of rotor relative angular velocity with the help of internal moment from the main body So rotor capture means an ldquoinstantaneous freezingrdquo of rotor with respect to the main body The capture can be performed with the help of gear meshing friction clutch or other methods
27
(6)
II6 Analytical solutions of motion equations
0e e ex y zM M M
A B C D
12 121
12 122
0
0
0
0
si
si
M if t tM
otherwise
M if t tM
otherwise
12 12 12sS M t I
1 12 2 12S S
1 1 12c c st t t
1 0
12
122
ISp
A IAS
A I
1 0 Conjugate spinup of rotors 1 2
Rotor 1 capture
Rotor 2 capture
2 2 1c c ct t t
1 2
121 2
0 0
c c
c c
t t tp IS
P t t tA I
Two serial captures of conjugate rotors bring to piecewise constant angular velocity of the main body
The main body performed the rotation about Ox axis by finite angle 12 2 1
c c
x
IS t t
A I
28
1 3 5 2 4 6
0 1 2 3
1 0
c c c c c c c cstart finish
c c c cstart start start start
t t t t t t t t
t t t t
0 1
2 3
2 2 2
cos sin2 2
sin sin2 2
c cstart start
c cstart start
c c c cstart finish finish start
t t t tPt t
t t t tQ Rt t
P Q R t t t T t t
1 2 t t t p P q Q r R
Letrsquos assume synchronically captures of coresponded conjugate rotors 1 2 3 4 5 6 and coincidence of the frame Oxyz initial position and the fixed frame OXYZ
Angular velocities between conjugate captures of rotors
Solutions of kinematic equations (5)
cos cos cosT
P Q R
T
e
The main body performed finite rotation about vector e by angle χ
(18)
(20)
(19)
(21)
29II7 Numerical simulation of reorientation process
const 0 1 135 246
i s cj jj j j
i s cj jj j j
jj
M M H t H t t H t t
M M H t H t t H t t
M j j
Two sets of results of numerical simulation
1 4 5(0) (0) (0) 0 (0) 100 1 s ω
ν = 300 Nms
H(t) is Heaviside function
FigA - zero value of angular momentum and different inertia moments of main body
Fig A Fig B
Fig4 - reorientation process at nonzero system angular momentum
30
__________________________________________________________
The main properties of the attitude stabilization and control of SC (and multirotor systems) have been examined
Research into attitude motion of the one-body-SC dual-spin SC and spider-type-SC is very complicated
Nontrivial and chaotic modes are possible in the SC attitude motion
Conclusion
- Slide 1
- Outline
- Part 1 - Introduction to Attitude Dynamics and Control
- Slide 4
- Spin stabilization
- Spin Stabilization Dual-Spin Spacecraft
- Spin Stabilization Dual-Spin Spacecraft (2)
- Spin Stabilization Dual-Spin Spacecraft (3)
- Spin Stabilization Dual-Spin Spacecraft (4)
- Gravity Gradient Stabilization
- Magnetic Stabilization
- Aerodynamic Stabilization
- Actuators
- Actuators (2)
- Actuators (3)
- Main Equations of Angular Motion of Rigid Body (Attitude Motion
- Main Properties of the Free Angular Motion of Rigid Body (Attit
- Main Properties of the Free Angular Motion of Rigid Body (Attit (2)
- Part 2 ndash Research Results
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
-
II The spider-type systems motion 24
m r K K K
1 2
3 4
5 6
4 2 m r
Ap p
Bq J I q I
Cr r
K K
ed
dt
Kω K M
12 56 34
34 12 56
56 34 12
ex
ey
ez
Ap I C B qr I q r M
Bq I A C pr I r p M
Cr I B A pq I p q M
4 2
4 2 4 2
iji j A A J I
B B J I C C J I
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i ex x
i e i ey y
i e i ez z
I p M M I p M M
I q M M I q M M
I r M M I r M M
(1)
(2)
(3)
(4)
II1 Angular momentum of the system in projections onto axes of the frame Oxyz
II2 The motion equations of the multirotor system
25
1 1
1 1
4 2
4 2 4 2
N Nij
il jl ll l
N N
l ll l
A A J NI
B B J NI C C J NI
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i el l lx l l lx
i e i el l ly l l ly
i e i el l lz l l lz
I p M M I p M M
I q M M I q M M
I r M M I r M M
0
1
2
3
cos 2
cos sin2
cos sin2
cos sin2
2 λ Θ λ
0
1
2
3
0
0
0
0
p q r
p r q
q r p
r q p
λ Θ
(4rsquo)
II3 The Euler parameters
(5)
26II4 The conjugate spinups and captures
Def1 Conjugate rotors are paired rotors located in the same layer on the opposite rays For example rotor 3N and rotor 4N are conjugate rotors (also rotor 12 and rotor 22 etc)
Def2 Conjugate spinup mean a process of spinning up conjugate rotors in opposite directions up to a desired value of relative angular velocity with the help of internal moments from main body Velocities of conjugate rotors will be equal in absolute value and opposite in sign
Def3 Rotor capture is an immediate deceleration of rotor relative angular velocity with the help of internal moment from the main body So rotor capture means an ldquoinstantaneous freezingrdquo of rotor with respect to the main body The capture can be performed with the help of gear meshing friction clutch or other methods
27
(6)
II6 Analytical solutions of motion equations
0e e ex y zM M M
A B C D
12 121
12 122
0
0
0
0
si
si
M if t tM
otherwise
M if t tM
otherwise
12 12 12sS M t I
1 12 2 12S S
1 1 12c c st t t
1 0
12
122
ISp
A IAS
A I
1 0 Conjugate spinup of rotors 1 2
Rotor 1 capture
Rotor 2 capture
2 2 1c c ct t t
1 2
121 2
0 0
c c
c c
t t tp IS
P t t tA I
Two serial captures of conjugate rotors bring to piecewise constant angular velocity of the main body
The main body performed the rotation about Ox axis by finite angle 12 2 1
c c
x
IS t t
A I
28
1 3 5 2 4 6
0 1 2 3
1 0
c c c c c c c cstart finish
c c c cstart start start start
t t t t t t t t
t t t t
0 1
2 3
2 2 2
cos sin2 2
sin sin2 2
c cstart start
c cstart start
c c c cstart finish finish start
t t t tPt t
t t t tQ Rt t
P Q R t t t T t t
1 2 t t t p P q Q r R
Letrsquos assume synchronically captures of coresponded conjugate rotors 1 2 3 4 5 6 and coincidence of the frame Oxyz initial position and the fixed frame OXYZ
Angular velocities between conjugate captures of rotors
Solutions of kinematic equations (5)
cos cos cosT
P Q R
T
e
The main body performed finite rotation about vector e by angle χ
(18)
(20)
(19)
(21)
29II7 Numerical simulation of reorientation process
const 0 1 135 246
i s cj jj j j
i s cj jj j j
jj
M M H t H t t H t t
M M H t H t t H t t
M j j
Two sets of results of numerical simulation
1 4 5(0) (0) (0) 0 (0) 100 1 s ω
ν = 300 Nms
H(t) is Heaviside function
FigA - zero value of angular momentum and different inertia moments of main body
Fig A Fig B
Fig4 - reorientation process at nonzero system angular momentum
30
__________________________________________________________
The main properties of the attitude stabilization and control of SC (and multirotor systems) have been examined
Research into attitude motion of the one-body-SC dual-spin SC and spider-type-SC is very complicated
Nontrivial and chaotic modes are possible in the SC attitude motion
Conclusion
- Slide 1
- Outline
- Part 1 - Introduction to Attitude Dynamics and Control
- Slide 4
- Spin stabilization
- Spin Stabilization Dual-Spin Spacecraft
- Spin Stabilization Dual-Spin Spacecraft (2)
- Spin Stabilization Dual-Spin Spacecraft (3)
- Spin Stabilization Dual-Spin Spacecraft (4)
- Gravity Gradient Stabilization
- Magnetic Stabilization
- Aerodynamic Stabilization
- Actuators
- Actuators (2)
- Actuators (3)
- Main Equations of Angular Motion of Rigid Body (Attitude Motion
- Main Properties of the Free Angular Motion of Rigid Body (Attit
- Main Properties of the Free Angular Motion of Rigid Body (Attit (2)
- Part 2 ndash Research Results
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
-
25
1 1
1 1
4 2
4 2 4 2
N Nij
il jl ll l
N N
l ll l
A A J NI
B B J NI C C J NI
1 1 1 2 2 2
3 3 3 4 4 4
5 5 5 6 6 6
i e i el l lx l l lx
i e i el l ly l l ly
i e i el l lz l l lz
I p M M I p M M
I q M M I q M M
I r M M I r M M
0
1
2
3
cos 2
cos sin2
cos sin2
cos sin2
2 λ Θ λ
0
1
2
3
0
0
0
0
p q r
p r q
q r p
r q p
λ Θ
(4rsquo)
II3 The Euler parameters
(5)
26II4 The conjugate spinups and captures
Def1 Conjugate rotors are paired rotors located in the same layer on the opposite rays For example rotor 3N and rotor 4N are conjugate rotors (also rotor 12 and rotor 22 etc)
Def2 Conjugate spinup mean a process of spinning up conjugate rotors in opposite directions up to a desired value of relative angular velocity with the help of internal moments from main body Velocities of conjugate rotors will be equal in absolute value and opposite in sign
Def3 Rotor capture is an immediate deceleration of rotor relative angular velocity with the help of internal moment from the main body So rotor capture means an ldquoinstantaneous freezingrdquo of rotor with respect to the main body The capture can be performed with the help of gear meshing friction clutch or other methods
27
(6)
II6 Analytical solutions of motion equations
0e e ex y zM M M
A B C D
12 121
12 122
0
0
0
0
si
si
M if t tM
otherwise
M if t tM
otherwise
12 12 12sS M t I
1 12 2 12S S
1 1 12c c st t t
1 0
12
122
ISp
A IAS
A I
1 0 Conjugate spinup of rotors 1 2
Rotor 1 capture
Rotor 2 capture
2 2 1c c ct t t
1 2
121 2
0 0
c c
c c
t t tp IS
P t t tA I
Two serial captures of conjugate rotors bring to piecewise constant angular velocity of the main body
The main body performed the rotation about Ox axis by finite angle 12 2 1
c c
x
IS t t
A I
28
1 3 5 2 4 6
0 1 2 3
1 0
c c c c c c c cstart finish
c c c cstart start start start
t t t t t t t t
t t t t
0 1
2 3
2 2 2
cos sin2 2
sin sin2 2
c cstart start
c cstart start
c c c cstart finish finish start
t t t tPt t
t t t tQ Rt t
P Q R t t t T t t
1 2 t t t p P q Q r R
Letrsquos assume synchronically captures of coresponded conjugate rotors 1 2 3 4 5 6 and coincidence of the frame Oxyz initial position and the fixed frame OXYZ
Angular velocities between conjugate captures of rotors
Solutions of kinematic equations (5)
cos cos cosT
P Q R
T
e
The main body performed finite rotation about vector e by angle χ
(18)
(20)
(19)
(21)
29II7 Numerical simulation of reorientation process
const 0 1 135 246
i s cj jj j j
i s cj jj j j
jj
M M H t H t t H t t
M M H t H t t H t t
M j j
Two sets of results of numerical simulation
1 4 5(0) (0) (0) 0 (0) 100 1 s ω
ν = 300 Nms
H(t) is Heaviside function
FigA - zero value of angular momentum and different inertia moments of main body
Fig A Fig B
Fig4 - reorientation process at nonzero system angular momentum
30
__________________________________________________________
The main properties of the attitude stabilization and control of SC (and multirotor systems) have been examined
Research into attitude motion of the one-body-SC dual-spin SC and spider-type-SC is very complicated
Nontrivial and chaotic modes are possible in the SC attitude motion
Conclusion
- Slide 1
- Outline
- Part 1 - Introduction to Attitude Dynamics and Control
- Slide 4
- Spin stabilization
- Spin Stabilization Dual-Spin Spacecraft
- Spin Stabilization Dual-Spin Spacecraft (2)
- Spin Stabilization Dual-Spin Spacecraft (3)
- Spin Stabilization Dual-Spin Spacecraft (4)
- Gravity Gradient Stabilization
- Magnetic Stabilization
- Aerodynamic Stabilization
- Actuators
- Actuators (2)
- Actuators (3)
- Main Equations of Angular Motion of Rigid Body (Attitude Motion
- Main Properties of the Free Angular Motion of Rigid Body (Attit
- Main Properties of the Free Angular Motion of Rigid Body (Attit (2)
- Part 2 ndash Research Results
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
-
26II4 The conjugate spinups and captures
Def1 Conjugate rotors are paired rotors located in the same layer on the opposite rays For example rotor 3N and rotor 4N are conjugate rotors (also rotor 12 and rotor 22 etc)
Def2 Conjugate spinup mean a process of spinning up conjugate rotors in opposite directions up to a desired value of relative angular velocity with the help of internal moments from main body Velocities of conjugate rotors will be equal in absolute value and opposite in sign
Def3 Rotor capture is an immediate deceleration of rotor relative angular velocity with the help of internal moment from the main body So rotor capture means an ldquoinstantaneous freezingrdquo of rotor with respect to the main body The capture can be performed with the help of gear meshing friction clutch or other methods
27
(6)
II6 Analytical solutions of motion equations
0e e ex y zM M M
A B C D
12 121
12 122
0
0
0
0
si
si
M if t tM
otherwise
M if t tM
otherwise
12 12 12sS M t I
1 12 2 12S S
1 1 12c c st t t
1 0
12
122
ISp
A IAS
A I
1 0 Conjugate spinup of rotors 1 2
Rotor 1 capture
Rotor 2 capture
2 2 1c c ct t t
1 2
121 2
0 0
c c
c c
t t tp IS
P t t tA I
Two serial captures of conjugate rotors bring to piecewise constant angular velocity of the main body
The main body performed the rotation about Ox axis by finite angle 12 2 1
c c
x
IS t t
A I
28
1 3 5 2 4 6
0 1 2 3
1 0
c c c c c c c cstart finish
c c c cstart start start start
t t t t t t t t
t t t t
0 1
2 3
2 2 2
cos sin2 2
sin sin2 2
c cstart start
c cstart start
c c c cstart finish finish start
t t t tPt t
t t t tQ Rt t
P Q R t t t T t t
1 2 t t t p P q Q r R
Letrsquos assume synchronically captures of coresponded conjugate rotors 1 2 3 4 5 6 and coincidence of the frame Oxyz initial position and the fixed frame OXYZ
Angular velocities between conjugate captures of rotors
Solutions of kinematic equations (5)
cos cos cosT
P Q R
T
e
The main body performed finite rotation about vector e by angle χ
(18)
(20)
(19)
(21)
29II7 Numerical simulation of reorientation process
const 0 1 135 246
i s cj jj j j
i s cj jj j j
jj
M M H t H t t H t t
M M H t H t t H t t
M j j
Two sets of results of numerical simulation
1 4 5(0) (0) (0) 0 (0) 100 1 s ω
ν = 300 Nms
H(t) is Heaviside function
FigA - zero value of angular momentum and different inertia moments of main body
Fig A Fig B
Fig4 - reorientation process at nonzero system angular momentum
30
__________________________________________________________
The main properties of the attitude stabilization and control of SC (and multirotor systems) have been examined
Research into attitude motion of the one-body-SC dual-spin SC and spider-type-SC is very complicated
Nontrivial and chaotic modes are possible in the SC attitude motion
Conclusion
- Slide 1
- Outline
- Part 1 - Introduction to Attitude Dynamics and Control
- Slide 4
- Spin stabilization
- Spin Stabilization Dual-Spin Spacecraft
- Spin Stabilization Dual-Spin Spacecraft (2)
- Spin Stabilization Dual-Spin Spacecraft (3)
- Spin Stabilization Dual-Spin Spacecraft (4)
- Gravity Gradient Stabilization
- Magnetic Stabilization
- Aerodynamic Stabilization
- Actuators
- Actuators (2)
- Actuators (3)
- Main Equations of Angular Motion of Rigid Body (Attitude Motion
- Main Properties of the Free Angular Motion of Rigid Body (Attit
- Main Properties of the Free Angular Motion of Rigid Body (Attit (2)
- Part 2 ndash Research Results
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
-
27
(6)
II6 Analytical solutions of motion equations
0e e ex y zM M M
A B C D
12 121
12 122
0
0
0
0
si
si
M if t tM
otherwise
M if t tM
otherwise
12 12 12sS M t I
1 12 2 12S S
1 1 12c c st t t
1 0
12
122
ISp
A IAS
A I
1 0 Conjugate spinup of rotors 1 2
Rotor 1 capture
Rotor 2 capture
2 2 1c c ct t t
1 2
121 2
0 0
c c
c c
t t tp IS
P t t tA I
Two serial captures of conjugate rotors bring to piecewise constant angular velocity of the main body
The main body performed the rotation about Ox axis by finite angle 12 2 1
c c
x
IS t t
A I
28
1 3 5 2 4 6
0 1 2 3
1 0
c c c c c c c cstart finish
c c c cstart start start start
t t t t t t t t
t t t t
0 1
2 3
2 2 2
cos sin2 2
sin sin2 2
c cstart start
c cstart start
c c c cstart finish finish start
t t t tPt t
t t t tQ Rt t
P Q R t t t T t t
1 2 t t t p P q Q r R
Letrsquos assume synchronically captures of coresponded conjugate rotors 1 2 3 4 5 6 and coincidence of the frame Oxyz initial position and the fixed frame OXYZ
Angular velocities between conjugate captures of rotors
Solutions of kinematic equations (5)
cos cos cosT
P Q R
T
e
The main body performed finite rotation about vector e by angle χ
(18)
(20)
(19)
(21)
29II7 Numerical simulation of reorientation process
const 0 1 135 246
i s cj jj j j
i s cj jj j j
jj
M M H t H t t H t t
M M H t H t t H t t
M j j
Two sets of results of numerical simulation
1 4 5(0) (0) (0) 0 (0) 100 1 s ω
ν = 300 Nms
H(t) is Heaviside function
FigA - zero value of angular momentum and different inertia moments of main body
Fig A Fig B
Fig4 - reorientation process at nonzero system angular momentum
30
__________________________________________________________
The main properties of the attitude stabilization and control of SC (and multirotor systems) have been examined
Research into attitude motion of the one-body-SC dual-spin SC and spider-type-SC is very complicated
Nontrivial and chaotic modes are possible in the SC attitude motion
Conclusion
- Slide 1
- Outline
- Part 1 - Introduction to Attitude Dynamics and Control
- Slide 4
- Spin stabilization
- Spin Stabilization Dual-Spin Spacecraft
- Spin Stabilization Dual-Spin Spacecraft (2)
- Spin Stabilization Dual-Spin Spacecraft (3)
- Spin Stabilization Dual-Spin Spacecraft (4)
- Gravity Gradient Stabilization
- Magnetic Stabilization
- Aerodynamic Stabilization
- Actuators
- Actuators (2)
- Actuators (3)
- Main Equations of Angular Motion of Rigid Body (Attitude Motion
- Main Properties of the Free Angular Motion of Rigid Body (Attit
- Main Properties of the Free Angular Motion of Rigid Body (Attit (2)
- Part 2 ndash Research Results
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
-
28
1 3 5 2 4 6
0 1 2 3
1 0
c c c c c c c cstart finish
c c c cstart start start start
t t t t t t t t
t t t t
0 1
2 3
2 2 2
cos sin2 2
sin sin2 2
c cstart start
c cstart start
c c c cstart finish finish start
t t t tPt t
t t t tQ Rt t
P Q R t t t T t t
1 2 t t t p P q Q r R
Letrsquos assume synchronically captures of coresponded conjugate rotors 1 2 3 4 5 6 and coincidence of the frame Oxyz initial position and the fixed frame OXYZ
Angular velocities between conjugate captures of rotors
Solutions of kinematic equations (5)
cos cos cosT
P Q R
T
e
The main body performed finite rotation about vector e by angle χ
(18)
(20)
(19)
(21)
29II7 Numerical simulation of reorientation process
const 0 1 135 246
i s cj jj j j
i s cj jj j j
jj
M M H t H t t H t t
M M H t H t t H t t
M j j
Two sets of results of numerical simulation
1 4 5(0) (0) (0) 0 (0) 100 1 s ω
ν = 300 Nms
H(t) is Heaviside function
FigA - zero value of angular momentum and different inertia moments of main body
Fig A Fig B
Fig4 - reorientation process at nonzero system angular momentum
30
__________________________________________________________
The main properties of the attitude stabilization and control of SC (and multirotor systems) have been examined
Research into attitude motion of the one-body-SC dual-spin SC and spider-type-SC is very complicated
Nontrivial and chaotic modes are possible in the SC attitude motion
Conclusion
- Slide 1
- Outline
- Part 1 - Introduction to Attitude Dynamics and Control
- Slide 4
- Spin stabilization
- Spin Stabilization Dual-Spin Spacecraft
- Spin Stabilization Dual-Spin Spacecraft (2)
- Spin Stabilization Dual-Spin Spacecraft (3)
- Spin Stabilization Dual-Spin Spacecraft (4)
- Gravity Gradient Stabilization
- Magnetic Stabilization
- Aerodynamic Stabilization
- Actuators
- Actuators (2)
- Actuators (3)
- Main Equations of Angular Motion of Rigid Body (Attitude Motion
- Main Properties of the Free Angular Motion of Rigid Body (Attit
- Main Properties of the Free Angular Motion of Rigid Body (Attit (2)
- Part 2 ndash Research Results
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
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29II7 Numerical simulation of reorientation process
const 0 1 135 246
i s cj jj j j
i s cj jj j j
jj
M M H t H t t H t t
M M H t H t t H t t
M j j
Two sets of results of numerical simulation
1 4 5(0) (0) (0) 0 (0) 100 1 s ω
ν = 300 Nms
H(t) is Heaviside function
FigA - zero value of angular momentum and different inertia moments of main body
Fig A Fig B
Fig4 - reorientation process at nonzero system angular momentum
30
__________________________________________________________
The main properties of the attitude stabilization and control of SC (and multirotor systems) have been examined
Research into attitude motion of the one-body-SC dual-spin SC and spider-type-SC is very complicated
Nontrivial and chaotic modes are possible in the SC attitude motion
Conclusion
- Slide 1
- Outline
- Part 1 - Introduction to Attitude Dynamics and Control
- Slide 4
- Spin stabilization
- Spin Stabilization Dual-Spin Spacecraft
- Spin Stabilization Dual-Spin Spacecraft (2)
- Spin Stabilization Dual-Spin Spacecraft (3)
- Spin Stabilization Dual-Spin Spacecraft (4)
- Gravity Gradient Stabilization
- Magnetic Stabilization
- Aerodynamic Stabilization
- Actuators
- Actuators (2)
- Actuators (3)
- Main Equations of Angular Motion of Rigid Body (Attitude Motion
- Main Properties of the Free Angular Motion of Rigid Body (Attit
- Main Properties of the Free Angular Motion of Rigid Body (Attit (2)
- Part 2 ndash Research Results
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
-
30
__________________________________________________________
The main properties of the attitude stabilization and control of SC (and multirotor systems) have been examined
Research into attitude motion of the one-body-SC dual-spin SC and spider-type-SC is very complicated
Nontrivial and chaotic modes are possible in the SC attitude motion
Conclusion
- Slide 1
- Outline
- Part 1 - Introduction to Attitude Dynamics and Control
- Slide 4
- Spin stabilization
- Spin Stabilization Dual-Spin Spacecraft
- Spin Stabilization Dual-Spin Spacecraft (2)
- Spin Stabilization Dual-Spin Spacecraft (3)
- Spin Stabilization Dual-Spin Spacecraft (4)
- Gravity Gradient Stabilization
- Magnetic Stabilization
- Aerodynamic Stabilization
- Actuators
- Actuators (2)
- Actuators (3)
- Main Equations of Angular Motion of Rigid Body (Attitude Motion
- Main Properties of the Free Angular Motion of Rigid Body (Attit
- Main Properties of the Free Angular Motion of Rigid Body (Attit (2)
- Part 2 ndash Research Results
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Slide 36
-