quadrotor om
TRANSCRIPT
SPRING SEMESTER REPORTIndoor Quad-rotor Control
M.E. Team Number 01Members:
ECE DEPARTMENT:
Jigar Patel: Team Leader
John Chung: Software/Hardware Engineer
Matthew Kishe: Team Webmaster/Test Engineer
ME DEPARTMENT:
Adam Sobiewski: Team Leader/Treasurer
Andrew Silva: Sponsor Liaison
Gabriel Morales: Mechanical Engineer
SPONSOR
ContentsI. Function Analysis..............................................................................................................2
II. Project Specifications........................................................................................................2
III. Operation Procedures...................................................................................................3
Hardware Assembly.............................................................................................................3
Firmware.............................................................................................................................7
IV. Addition Assembly Required.........................................................................................9
V. Troubleshooting................................................................................................................9
VI. Future Repair/Replacement..........................................................................................9
VII. Spare Parts.................................................................................................................10
Table of
FiguresFigure 1: Propeller Guard........................................................................................................2
Figure 2: Support Arm.............................................................................................................2
Figure 3: Protective housing....................................................................................................3
Figure 4: Landing gear and motor assembly...........................................................................4
Figure 5: Main frame Assembly1..............................................................................................5
Figure 6: X-frame Configuration1.............................................................................................5
Figure 7: PDB mounting1.........................................................................................................5
Figure 8: ESC cable connections1............................................................................................6
Figure 9: PX4 mounted onto the bottom of the frame.............................................................6
Figure 10: Cable connection for hardware...............................................................................7
Figure 11: QGC PX4FMU CONFIG/SCAN Screenshot.................................................................8
Figure 12: Installation instructions for protective housing.......................................................9
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I. Function AnalysisThe protective housing is comprised of eight (8) total parts consisting of four (4) support
arms and four (4) propeller guards, both shown below. The propeller guards enclose
each motor assembly to prevent it from coming into contact with any obstacle in the
event of a crash. The propeller guards are connected to the main quadcopter frame via
support arms. The support arms are designed to transfer the load from the propeller
guard through the center of mass of the quadcopter.
FIGURE 1: PROPELLER GUARD
FIGURE 2: SUPPORT ARM
II. Project SpecificationsThe protective housing shown below is expected to withstand any indoor obstacle impact
or crash resulting from flight failure to prevent damage to any of the quadcopter’s
components. In addition, the added weight of the protective housing is not likely to
decrease flight time by a substantial amount.
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FIGURE 3: PROTECTIVE HOUSING
Furthermore, the protective housing will protect the users from harm during handling of
quadcopter. In addition to disconnecting the battery, the protective housing will keep the
users hands and fingers outside of the propeller’s spinning radius. Eyes and hand
protection is still a requirement while handling the quadcopter.
III. Operation Procedures
Hardware Assembly3DR provides a well described guide for the hardware assembly of the quadcopter. This
manual can be found at the following link. The following are used in the assembly of the
quadcopter:
3DR Quad D Frame
o 2 fiberglass plates
o 1 fiberglass PX4
o I fiberglass accessory plate
o 4 aluminum arms (2 black-back, 2 blue-front)
o Fiberglass landing gear (legs)
o Power distribution board (PDB)
o 4 880kV motors
o 4 propellers (11” X 4.7”)
o 4 electronic speed controllers (ESCs)
o Misc. Parts (washers, nuts, screws, and spacers)
PX4FMU
PX4IO
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PX4FLOW
PPM sum receiver
Telemetry Module
Cables for connecting all the modules together
Refer to the site for detailed instructions on how to unbox and assemble a quadcopter.
Below are a summary of the steps for putting together the quadcopter.
a. Start with putting together the landing gear onto the arms with spacers in
between the legs, do this for all four arms (See Figure 4)
Parts used:
o Two M3X25mm screw (green)
o Two M3 metal washer (pink)
o Two M3X18mm spacers
o Four M3X5mm screws (blue)
b. Mount the motors onto the end of the arm. Insert the motor cables into the side of
the arm, do this for all four arms (See Figure 4)
Parts used:
o Two M3X5mm screws (blue)
o Two M3 lock washers (orange)
FIGURE 4: LANDING GEAR AND MOTOR ASSEMBLY1
c. Once all four arms are done, assemble the main frame top and bottom plates
(See Figure 5)
Four M3X30 mm screws (blue)
Four M3X25 mm screws (green)
Eight M3 metal nuts (pink)
Four M3 lock washers (orange)
Four M3X08 mm spacers
1 Image from http://store.3drobotics.com/products/3dr-quad-frame-kit-electronics
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Four 3X5mm screws (red)
FIGURE 5: MAIN FRAME ASSEMBLY1
d. Mount the PDB onto the four spacers in the middle of the bottom plate. Make sure
that the front arrow on the PDB matches the copters convention and
configuration type (‘X’ frame configuration). (See Figure 7)
FIGURE 6: X-FRAME CONFIGURATION1 FIGURE 7: PDB MOUNTING1
e. Connect the ESC cables to the respective motor cables. See Figure 8 to obtain the
correct directions for the motors. Directions are shown in Figure 6.
NOTE: Do not secure the ESCs until the directions have been verified
(this step is explained in the next section)
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FIGURE 8: ESC CABLE CONNECTIONS1
f. Mount the PX4FMU and PX4IO onto a plate and use spacers to attach it to the
bottom plate.
FIGURE 9: PX4 MOUNTED ONTO THE BOTTOM OF THE FRAME
g. Use double sided tape or Velcro to stick the RC receiver, and telemetry receiver
onto the top of the copter and use M3X8mm nylon screws to mount the PX4FLOW
onto the bottom of the accessory plate.
h. Use the figure below to make all the cable connections to the PX4FMU/IO board
(See
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FIGURE 10: CABLE CONNECTION FOR HARDWARE2
i. Once all the components are correctly connected move to the firmware section to
flash the firmware.
FirmwareThis section talks about setting up the PX4FMU along with the carrier PX4IO board. Make
sure you have an empty Micro SD card. First step is to install the firmware using
QGroundControl (QGC).
a. QGroundControl (QGC) Software
Download the most recent version of QGroundControl which can be downloaded
by clicking here and then follow these steps to get ready for your first flight
b. PX4FMU Firmware
In QGC click on the CONFIG then on the big green SCAN button. Click on the
flash/upgrade firmware button to load the firmware onto the PX4FMU.
2 High resolution image http://pixhawk.org/_media/airframes/x5/buildlog_q_x5_26.jpg?cache=
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FIGURE 11: QGC PX4FMU CONFIG/SCAN SCREENSHOT
c. PX4IO Firmware
Hold down the safety switch while powering on the PX4 to renter the boot loader
mode. If done correctly the red led on the IO board will flash rapidly. Let the FMU
boot normally, it will automatically upgrade the processor firmware.
d. Airframe Setup
Once the firmware is flashed onto the board the first thing to do in QGC is to
make sure the right Airframe has been selected. This is done by clicking on the
AIRFRAME CONFIG button on the left toolbar and following the onscreen
instructions.
e. Sensor Calibration
Next is the sensor calibrations which is done by clicking on the SENSOR
CALIBRATION from the left toolbar. Follow the on-screen instructions to calibrate
all the sensors (i.e. Magnetometer, Gyro meter, and Accelerometer)
f. RC Calibration
After the sensors are calibrated, the remote controller (RC) needs to be calibrated
to set the min and max values for the RC inputs. This is done by clicking on the
RC CALIBRATION button from the left toolbar and following instructions.
g. Manual Mode flight Test
Once all the previous steps are successfully completed a manual mode flight test
is to be performed. The USB will not provide sufficient power to spin the motors
and thus the battery should be connected to the system and the USB shall no
longer be connected. Follow the steps below to enter Manual Mode:
1. Make sure RC calibration is done first
2. Start QGC (optional)
3. Connect PX4 board to the battery
4. Connect PX4 board to USB (for data collection if telemetry is not
connected)
5. Turn on the RC transmitter
6. Hold down the safety switch (blinking red light should now be solid red
indicating ready to arm status)
7. Hold the RC throttle stick to the bottom left (this is the method for arming
the copter)
8. You should hear the audio alarm for “ARMED”
9. Release the safety switch
10. The servos should now move
If you are having trouble make sure the Throttle and Yaw channels are not
reversed and also make sure that the ESCs are calibrated.
h. Telemetry on PX4
Plug in the telemetry to the board using a 3DR Radio adapter cable to the UART2
port of the board.
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IV. Addition Assembly Required This section talks about the
installation of the protective
housing. Twenty-four (24)
M3x25.4mm screws and M3 nuts
are required for installation. Pre-
drilled holes and support arm and
propeller guard should be lined
up and secured using a screw
and nut. The arrows and solid
sots in Figure 2 illustrate where
each screw and nut should be
placed.
V. TroubleshootingMost of the troubleshooting requires research since there are many stages at which
troubleshooting may occur. Primary sites referred to were the manufactures’ sites. (i.e.
PX4, 3DR etc.)
VI. Future Repair/ReplacementThis section talks about the future repairs and replacements which are specific to the
future goals of the project. Major code modifications and replacements are anticipated to
implement the Velocity based flight control. This involves modifications to the PX4
firmware. Specific files that need to be modified are listed below:
The multirotor velocity controller folder contains the source code that needs
modifications to implement the velocity controller. (Filename:
mc_vel_control_main.cpp)
The PX4 depends on a RC script file to initialize all the sensors, IO board, Inter
Process Communication (IPC), PX4 Flow, MavLink (communication protocols) and
the controller module. This file needs to be updated onto the SD card for the
initialization.
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FIGURE 12: INSTALLATION INSTRUCTIONS FOR PROTECTIVE HOUSING.
The PX4 also requires configuration to set the controller to recognize the vehicle
type, and to set the parameters to be used by the quadcopter. i.e PWM cutoff
frequencies.
In addition to the controls listed above, spare parts for each component of the protective
housing will be fabricated in case of failure of one piece. The parts were designed to be
easily interchangeable if a piece were to fracture. Prior to each flight, all screws, nuts,
and components of the protective housing, as well as the entire quadcopter system,
should be checked for any issues to prevent catastrophic failure during flight.
VII. Spare PartsThis section provides the specs and descriptions of the required spare parts needed to
minimize downtime in case of crashes. Click here to buy these parts.
TABLE 1: SPARE PARTS LIST
Part Name Specifications Description Images
Propellers 11 X 4.711 X 4.7P
Used for flying the copter, the letter P which stands for pusher is used for the clockwise rotating arms. While the propellers without the P are used for the counter-clockwise rotating arms.
SpacersM3 X 24mmM3 X 08 mmM3 X 18 mmM3 X 30 mm
Black nylon spacers of varied lengths.*NOTE: have lots of these on hand, easy to break hard to find.
Legs N/A
Legs break easily specially when learning flight and landing. Having spares or re-designing legs will be helpful.
BatteryLiPo Battery 3S3300 mAh
Lithium Polymer battery 20C discharge rate
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Dean Connectors
MaleFemale
Dean connectors are widely used all through the copter components. The motor board, ESCs, batteries all use male/female dean connectors.
ESCs 20A-BEC
Electronic Speed Controllers (ESCs) a spare set would be helpful (4 ESCs)
Motors 880 kVSpare set of motors (4 motors)
Arms3DR Aluminum Arms
Spare arms needed in case of crashes, blue is for front, black is for the back.
Support Arms
Protective Housing Support Arms
Spare arms are essential in the event of a crash resulting in a compromised arm. Fabrication takes 24 hours to cure.
Propeller Guards
Protective Housing Propeller Guards
Due to long and tedious fabrication time, spare propeller guards are essential in the event of a crash resulting in a fracture.
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