Introduction toAutomatic Control

Systems

Basic Information• Instructor Contact Information

– Degang Chen, 2134 Coover Hall– djchen@iastate.edu; 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– Jon Watson, 3201 Coover Hall– Office Hour: 1:00-2:00 pm, TR, ALC Village B, #6– E-mail: jonrwat@gmail.com; – Voice phone: 515-520-9569

Class Webpage• http://class.ece.iastate.edu/djchen/ee475/2009

• Please check the page for– Any announcement– Class notes– HW assignments– Lab assignments– Project requirements– Class policy and other info

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%

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

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

Textbook• Automatic Control Systems, Golnaraghi

and Kuo, ninth edition, Wiley, 2009

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Other References

Other References

Other References

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 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 SystemsOpen-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 UsedPosition 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

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

Idle-speed control system.

Figure 1-5 (p. 5)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.