chapter 1 2014r

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MAAE 4500

Feedback Control Systems

Professors Nitzsche and Ahmadi

Mechanical and Aerospace Engineering

MAAE4500: Feeback Control 2

Course Information

• Textbook:

– Text Book: Modern Control Engineering (5th Edition)

by Katsuhiko Ogata. Prentice Hall, Upper Saddle

River, New Jersey (available in the bookstore)

– Additional Reference: Control Systems Engineering

(6th Edition) by Norman Nise, Wiley 2010

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Course Information

Understand how the dynamic systems behave

Define the desired behaviour: using performance

criteria for controlled system

Learn how to design controllers to achieve the

desired behaviour

Note: we do the above in time domain or frequency

domain

What we learn in this course:

Motivation: Systems do not behave exactly as we expect and

we need to control them to obtain the desired behaviour


Course Information

Course communication: all through CU Learn

There are no notes for this course. If any further

material is used outside the suggested text, then some

notes will be posted

Evaluation: Final 60%

2 Quizzes 40%

Total 100%

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MATLAB

MATLAB is an important tool in controls

engineering (with several toolboxes).

MATLAB with “Controls Toolbox” license is

available at Carleton undergraduate labs.

Textbook examples and sssignments will

require MATLAB

MATLAB is not required for evaluation

(Quizzes or Final)


Assignments

Will consist of written problems.

Posted online about a week before the due dates.

Should do the assignments on your own to succeed.

Answers will be posted after the due dates.

Some assignments are hands on and would require

knowledge of Matlab (in general good tools to know in

the future).

Extra suggested problems may be posted.

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Quizzes

Will consist of written problems

Quiz 1: in October (date TBD)

Quiz 2: in November (date TBD)

Closed book with formula sheet and calculators

are allowed

Material: all material covered up to one lecture

before the Quiz date


Final Exam

University scheduled

– Closed-book and calculators allowed

– The final examination is for evaluation purposes

only and will NOT be returned to the student

– Material covered: All

– Exam and the Quizzez may contain both written

and multiple choice questions

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Lecturers & TA Office Hours

Section A: Loeb C164, WF 16:00 – 17:30

Prof. Mojtaba Ahmadi (6208 CB)

Phone: 613 520-2600 ext. 4057

Email: [email protected]

Section B: Azrieli Theatre 101, TR 14:30 – 16:00

Prof. Fred Nitzsche (6214D VSIM)

Phone: 613 520-2600 ext. 5660

Email: [email protected]

Sections A and B lectures and evaluations are the same:


Lectures

Mainly use the blackboard, occasionally slides

Attendance is very important

Follow book chapters according to the schedule

Key to success: distribution of your work load over the term (complete the assignments)

Only occasionally may post lecture materials in addition to the text book.

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Other Notes

Students that require any accommodation

should do so early on during the term (2

weeks into the term). Please read the

statement on the outline. Students that need

to register with PMC, please do so as soon as

possible.


Chapter 1

Introduction

7


Speed Control System

(James Watt, 1769)


Water-level Float Regulator

(I. Polzunov, Russia, 1765)

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Control Systems Development

Closed-loop Control Example

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• How do we control the position of a mass?

• Dynamic behavior and governing equations?

• Feedback: Sensor, actuator, control law?

• Control law selection and its impact on the

dynamic behavior?

F M

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Closed- and Open-loop Systems

• Closed-loop or feedback control systems

– A system that maintains a prescribed relationship

between the output and a reference input signal in

the presence of disturbances

– A control signal is generated by the controller and

added to the disturbances to correct the system

response

• Open-loop systems

– Systems for which the output signal has no effect

on the control signal

Closed-loop Control Example

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• Controlling a modern elevator

• Actuator?

• Sensor?

• Dynamic equations / behavior?

• Disturbance / Disturbance Rejection

• Control law selection and its impact on the

dynamic behavior? F

M

Mg

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Feedback control’s three elements:

Sensors, Actuators, Control law (implementation options)

Feedback structure:

Plant Control

Sensor

r e (error) u (input)

d (disturbance)

y (output)

(measurement noise)

Ref.

input

v y = Controlled variable

u= manipulated variable

Control Objectives

• Output, y, should follow the input r or:

• y(t) / r(t) 1 as t ∞

• Equivalently, error should converge to zero:

• e(t) 0 as t ∞

• The output, y, should be least affected by disturbance d:

• (y/d) 0 as t ∞

• The output, y, should be least affected by measurement

noise, v:

• (y/v) 0 as t ∞

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Open Loop control has:

– Simpler implementation

– Lower cost

– No stability issue

– Convenience with hard-to-measure outputs

But has issues:

– Prone to errors in the presence of disturbance

– Prone to system parameter uncertainty

Therefore:

– Mostly feedback control is used


Example: Closed-loop (“Human Feedback”) Control

input output

controller actuator plant/process

sensors

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Closed-loop (“Automatic Feedback”) Control


Mechatronic Examples

Embedded computer to execute control tasks

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Structure of Computer-Controlled Systems

Mechanical System To be controlled

Sensors Actuators

Signal Conditioning

A/D, Filter

Signal Conditioning

D/A, Amp.

Digital Controller (computer)

Control Algorithm

Input Devices

User Interface

user


Examples

http://mars.jpl.nasa.gov/MPF/mpf/rover-ops.html

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Examples

Legged robots: multiple joint control and balance


Research example: Robotic Welding

• Nonlinear process

• Adaptive control

• Multiple control loops:

position, force, speed,

temperature, etc.

Robot force and position control for welding of

composites (Carleton-NRC)

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Research: Robot for Wind Tunnel (CTS)

• Multiple control loops

• Aerodynamic disturbance

Robot Manipulators optimal planning and control

Carleton-NRC


Research examples from (ABL Lab)

Advanced Biomechatronics and Locomotion Lab

Bipedal walking and human postural stability

Learning controllers

Nonlinear control

ABL-B1: simulation

and design

pruning.avi

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Bipedal walking and human postural stability

Learning controllers

Nonlinear control

ABL-B1: Completed

and control being

implemented




Virtual Gait Retraining – Rehabilitation (ViGR)

• Human-robot interaction

• Force controlled systems

• Design for control

Walking 4x.wmv

RehabRobotCircleTest.mov

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Intelligent Assistive Devices

• Assist-as-needed control for enhanced rehabilitation

• Human-robot interaction control

• Muscle signal processing

GaitEnable System (GE)

■ GaitEnable – User interaction

– Nonlinear control, stability issues

AK1_attached.AVI

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Notes :

• Don’t miss the opportunity to apply for OGS and

NSERC Scholarships (usually due in Fall).

• We are always looking for good graduate students


Control Theory

Introduction to Control Systems

The Laplace Transform (Review)

Mathematical Modeling of Dynamic Systems

Root-Locus Analysis

Control Systems Design by the Root-Locus Method

PID Controls

Frequency Response and Analysis of Systems (Some Review)

Control System Design in Frequency Domain

Contents: Classical Control Theory (this course)

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Control Theory

State space modeling and control

Nonlinear control theory

Identification and adaptive control

Robust control

Optimal control

Digital control

Estimation

...

Contents: Modern control theory (after this course)


• Review your past material on systems including

Laplace Transforms and related theorems. This is

very important.

• Review the feedback control concept by trying to

find a few real-life problems. Devise it into elements

involved in a control system. You should be able to find

numerous examples.

Till your next lecture:

chapter 1 2014r

Documents

feeback control

control systems engineering

final maae4500

modern control engineering

matlab matlab

quiz date maae4500

desired behaviour maae4500

aerospace engineering