ee 475 automatic control systems fall 2010 mwf 11:00-11:50 am 1252 howe hall
TRANSCRIPT
EE 475Automatic Control
Systems
Fall 2010MWF 11:00-11:50 am
1252 Howe Hall
Class Webpage• http://class.ece.iastate.edu/djchen/ee475/2010
• Please check the page for– Any announcement– Class notes– HW assignments– Lab assignments– Project requirements– Class policy and other info
Basic Information• Instructor Contact Information
– Degang Chen, 2134 Coover Hall– [email protected]; 294-6277– Office Hour: MWF 12:00 – 2:00 pm– Or any other time convenient to you – Please include "EE475" in the subject line in all email communications to avoid
auto-deleting or junk-filtering
• TA– Yu Tian, 3102 Coover Hall– Office Hour: ?? (Most likely none. Only 5 hrs budget.)– E-mail: [email protected]– Voice Phone: 515-708-4059
Christofferson Craig [email protected] Stephen [email protected] Joshua [email protected]
Stars of the class
Final Grade Weighting Schedule
• Homework average: 15%• Midterm exam1: 20%• Midterm exam2: 20%• Final exam: 30%• Quizzes: 15%• Discretionary bonus: 0-5%• Fixed Grading Scale:
A: 95 – 100% A–: 90 – 95%B+: 85 – 90 % B: 80 – 85%B–: 75 – 80% C+: 70 – 75%C: 65 – 70% C–: 60 – 65%F: <60%
Catalog Description
• E E 475. Automatic Control Systems. (3-0) Cr. 3. F.Prereq: 324. Stability and performance analysis of automatic control systems. The state space, root locus, and frequency response methods for control systems design. PID control and lead-lag compensation. Computer tools for control system analysis and design. Nonmajor graduate credit.
Prerequisite by topics
• Knowledge and proficiency in Matlab• Concept and solution of linear ordinary
differential equations• Laplace transform and its applications• Poles, zeros, transfer functions, frequency
response, Bode plots• Vectors and matrices• Complex numbers
OBJECTIVES• On completion of EE 475, the student will be able to do the following either by hand or with the
help of computation tools such as Matlab: – Define the basic terminologies used in controls systems– Explain advantages and drawbacks of open-loop and closed loop control systems– Obtain models of simple dynamic systems in ordinary differential equation, transfer function, state space,
or block diagram form– Obtain overall transfer function of a system using either block diagram algebra, or signal flow graphs, or
Matlab tools.– Compute and present in graphical form the output response of control systems to typical test input signals– Explain the relationship between system output response and transfer function characteristics or pole/zero
locations– Determine the stability of a closed-loop control systems using the Routh-Hurwitz criteria– Analyze the closed loop stability and performance of control systems based on open-loop transfer
functions using the Root Locus technique– Design PID or lead-lag compensator to improve the closed loop system stability and performance using the
Root Locus technique– Analyze the closed loop stability and performance of control systems based on open-loop transfer
functions using the frequency response techniques– Design PID or lead-lag compensator to improve the closed loop system stability and performance using the
frequency response techniques
Topics Covered• Review of signal systems concepts and techniques as applied to control
system• Block diagrams and signal flow graphs• Modeling of control systems using ode, block diagrams, and transfer
functions• Modeling and analysis of control systems using state space methods• Analysis of dynamic response of control systems, including transient
response, steady state response, and tracking performance.• Closed-loop stability analysis using the Routh-Hurwitz criteria• Stability and performance analysis using the Root Locus techniques• Control system design using the Root Locus techniques• Stability and performance analysis using the frequency response techniques• Control system design using the frequency response techniques• If there is time, Control system design using the state space techniques
Student behavior expectations• Full attendance expected, except with prior-notified
excuses• On-time arrival• Active participation
– Ask questions– Answer questions from instructor or students
• Be cordial and considerate to students and TA• Help each other in reviewing notes, HW, Matlab• Promptly report/share problems/issues, including
typos on slides, or misspoken words from instructor
Prohibited behaviors
• Any foul language or gestures• Comments to other students that are
discriminatory in any form• Any harassments as defined by the university• Academic dishonesty
• No alcohol, drugs, or any other illegal / improper substances
Accommodation/Assistance
• Please let me know if you – Have any special needs– Have disability in any form– Have any medical/mental/emergency conditions– Have field trip / interview– Have special requests– Want me to adjust lecture contents/pace
• Can also consult me if you – Would like to seek advice on any professional or personal
issues– Would like to have certain confidential discussions
collaboration and helping each other
• For tasks intended for group work, you are expected to find a partner and share the tasks among the group members. In a group project, effective teamwork is critical to maximize the productivity of the whole group. In the submitted work, identify components and indicate percentage contribution by each member to each component.
• For tasks not intended for group work, individual submission is required. In this case, you are encouraged to discuss among your friends on how to attack problems. However, you should write your own solution. Copying other people’s work is strictly prohibited.
Academic dishonesty
• Cheating is a very serious offense. It will be dealt with in the most severe manner allowable under University regulations. If caught cheating, you can expect a failing grade and initiation of a cheating case in the University system.
• Basically, it’s an insult to the instructor, the department and major program, and most importantly, to the person doing the cheating. Just don't.
• If in doubt about what might constitute cheating, send e-mail to your instructor describing the situation. If you notice anyone cheating, please report it to the instructor or the TA. Do not deal with it yourself.
Discrimination
• State and Federal laws as well as Iowa State University policies prohibit any form of discrimination on the basis of race, color, age, religion, national origin, sexual orientation, gender identity, sex, marital status, disability, or status as a U.S. veteran. Language or gestures of discriminatory nature will not be tolerated. Severe cases will be reported to appropriate offices. See ISU policies at http://www.hrs.iastate.edu/hrs/files/reaffirmation.pdf
• Let us make every effort to work together and create a positive, collegial, caring, and all-supportive learning environment in our classroom, laboratory, TA office, and instructor office.
Disability accommodation
• Individuals with physical or mental impairments who are otherwise qualified to perform their work or pursue their studies may request reasonable accommodations to enable them to work or continue their studies.
• If you believe you have learning disability, you must contact Student Disability Resources at the Academic Success Center to initiate the accommodation process.
Accommodation for religion based conflict
• Iowa State University welcomes diversity of religious beliefs and practices, recognizing the contributions differing experiences and viewpoints can bring to the community. Students with religion based conflict should talk to the instructor and appropriate university offices to request accommodations at the earliest possible time.
Control Systems History
• Watt, steam engine speed control governor• Black, feedback amplifiers• Minorsky, ship steering stability• Nyquist, closed-loop stability from open-loop• Hazen, Servomechanisms• Bode, Bode plot, and BP based control design• Evans, root locus plot, RL based design• Kalman, state space, controllability, Kalman filter• Anderson…, linear optimal control
Figure 1-1 Speed control system.
• Bellman, dynamic programming• Pontryagin, maximum principle• Lyapunov, nonlinear systems• Sastry…, adaptive control• Arimoto, learning control• Doyle…, robust control• Byrnes/Isidori, nonlinear regulation• Devasia/Chen/Paden, stable inversion• Kokotovic, backstepping
Control Systems History
Control System Terminology
• Input - Excitation applied to a control system from an external source.
• Output - The response obtained from a system
• Feedback - The output of a system that is returned to modify the input.
• Error - The difference between the reference input and the output.
Negative Feedback Control System
CONTROLLERCONTROLLED DEVICE
FEEDBACK ELEMENT
+ ++
-
Types of Control Systems
Open-Loop– Simple control system which performs its function
with-out concerns for initial conditions or external inputs.
– Must be closely monitored.Closed-Loop (feedback)
– Uses the output of the process to modify the process to produce the desired result.
– Continually adjusts the process.
Advantages of a Closed-Loop Feedback System
Increased Accuracy– Increased ability to reproduce output with varied input.
Reduced Sensitivity to Disturbance– By self correcting it minimizes effects of system changes.
Smoothing and Filtering– System induced noise and distortion are reduced.
Increased Bandwidth– Produces sat. response to increased range of input
changes.
Major Types of Feedback Used
Position Feedback– Used when the output is a linear distance or
angular measurement.Rate & Acceleration Feedback
– Feeds back rate of motion or rate of change of motion (acceleration)
– Motion smoothing– Uses a electrical/mechanical device call an
accelerometer
PresentPosition
FuturePosition
Ship’s Heading
Pres
ent R
ange
Future Range
Range ChangeBearing Change
Present
Bearing
Fire Control Problem
A German anti-aircraft 88 mm gun with its fire-control computer from World War II.
Displayed in the Canadian War Museum.
Fire Control Problem
• Input– Target data– Own ship data
• Computations– Relative motion procedure– Exterior ballistics procedure
Fire Control Problem• Solutions
– Weapons time of flight– Bearing rate– Line of Sight(LOS): The line between the target and the firing
platform– Speed across LOS– Future target position– Launch angles
• Launch azimuth• Launch elevation
– Weapon positioning orders• The above determines weapon trajectory: The line the weapon must
travel on to intercept the target.
The Iterative Process to the Fire Control Solution
Step 1
Step 2
Step 3 Last Step
A 3-Dimensional Problem
Horizontal Reference Plane
Line of Sight
Present R
ange
Target Elevation
GunElevation
Solving the Fire Control Problem
Continuously MeasurePresent Target Position
Stabilize Measured Quantities
Compute RelativeTarget Velocity
BallisticCalculations
Relative Motion Calculations
Time of Flight
Future TargetPosition
Prediction Procedure
Unstabilized Launch Angles
Environmental Inputs
Launch Angles (Stabilized)
Weapons Positioning orders
Figure 1-2 Temperature control system.
Figure 1-3 Block diagram of an engineering organizational system.
Idle-speed control system.
Solar collector field.
Conceptual method of efficient water extraction using solar power.
Important components of the sun-tracking control system.
a. system concept;b. detailed layout;c. schematic;d. functional block diagram
Antenna azimuth position control system:
(a)
(b)
(c)
a. Video laser discplayer;b. objective lensreading pits on alaser disc;c. optical path forplayback showingtracking mirror rotated by a control system to keep the laser beam positioned on the pits.
© Pioneer Electronics, Inc.
Computer hard disk drive,
showing disks and read/write head
Courtesy of Quantum Corp.
Response of a position control system showing
effect of high and low controller
gain on the output response
High gain; fast but oscillating
Control goal; fast reaction, lower overshoot, less settling time
The control system design process
Aircraft attitude defined
Winder
© J. Ayers, 1988.
Control of a nuclear reactor
Grinder system
© 1997, ASME.
High-speed proportional solenoid valve
© 1996, ASME.
High-speed rail system showing pantograph and catenary
© 1997, ASME.