Slotine • Li APPLIED NONLINEAR CONTROL
! i
APPLIED
NONLINEAR
CONTROL
Jean-Jacques E Slotine
Weiping Li
Applied
Nonlinear
Control
JEAN-JACQUES E. SLOTINE
Massachusetts Institute of Technology
WEIPING LI
Massachusetts Institute of Technology'
Prentice Hall
Englewood Cliffs, New Jersey 07632
Library of Congress Cataloging-in-Publication Data
Slotine, J.-J. E. (Jean-Jacques E.)
Applied nonlinear control / Jean-Jacques E. Slotine, Weiping Li
p.
cm.
Includes bibliographical references.
ISBN 0-13-040890-5
1, Nonlinear control theory.
I. Li, Weiping.
QA402.35.S56 1991
629.8'312-dc20
II. Title.
90-33365
C1P
Editorial/production supervision and
interior design: JENNIFER WENZEL
Cover design: KAREN STEPHENS
Manufacturing Buyer: LORI BULWIN
= ^= © 1991 by Prentice-Hall, Inc.
^=&= A Division of Simon & Schuster
T k
Englewood Cliffs, New Jersey 07632
All rights reserved. No part of this book may be
reproduced, in any form or by any means,
without permission in writing from the publisher.
Printed in the United States of America
20 19 18 17 16 15 14 13 12 1]
ISBN D-13-DHDfiTa-S
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To Our Parents
Contents
Preface
1. Introduction
1.1 Why Nonlinear Control ?
1.2 Nonlinear System Behavior
1.3 An Overview of the Book
1.4 Notes and References
Part I: Nonlinear Systems Analysis
Introduction to Part I
14
2. Phase Plane Analysis
2.1 Concepts of Phase Plane Analysis
2.1.1 Phase Portraits
2.1.2 Singular Points
2.1.3 Symmetry in Phase Plane Portraits
18
20
22
2.2 Constructing Phase Portraits
2.3 Determining Time from Phase Portraits
2.4 Phase Plane Analysis of Linear Systems
2.5 Phase Plane Analysis of Nonlinear Systems
2.6 Existence of Limit Cycles
2.7 Summary
2.8 Notes and References
2.9 Exercises
xi
1
1
4
12
13
14
17
18
23
29
30
32
36
38
38
38
VI11
3. Fundamentals of Lyapunov Theory
3.1 Nonlinear Systems and Equilibrium Points
3.2 Concepts of Stability
3.3 Linearization and Local Stability
3.4 Lyapunov's Direct Method
3.4.1 Positive Definite Functions and Lyapunov Functions
3.4.2 Equilibrium Point Theorems
3.4.3 Invariant Set Theorems
61
68
3.5 System Analysis Based on Lyapunov's Direct Method
3.5.1 Lyapunov Analysis of Linear Time-Invariant Systems
3.5.2 Krasovskii's Method
3.5.3 The Variable Gradient Method
3.5.4 Physically Motivated Lyapunov Functions
3.5.5 Performance Analysis
83
86
88
91
58
77
3.6 Control Design Based on Lyapunov's Direct Method
3.7 Summary
3.8 Notes and References
3.9 Exercises
4. Advanced Stability Theory
4.1 Concepts of Stability for Non-Autonomous Systems
4.2 Lyapunov Analysis of Non-Autonomous Systems
4.2.1 Lyapunov's Direct Method for Non-Autonomous Systems
4.2.2 Lyapunov Analysis of Linear Time-Varying Systems
4.2.3 The Linearization Method for Non-Autonomous Systems
114
105
116
4.3 * Instability Theorems
4.4 * Existence of Lyapunov Functions
4.5 Lyapunov-Like Analysis Using Barbalat's Lemma
4.5.1 Asymptotic Properties of Functions and Their Derivatives
4.5.2 Barbalat's Lemma
123
122
4.6 Positive Linear Systems
4.6.1 PR and SPR Transfer Functions
4.6.2 The Kalman-Yakubovich Lemma
4.6.3 Positive Real Transfer Matrices
4.7 The Passivity Formalism
4.7.1 Block Combinations
132
4.7.2 Passivity in Linear Systems
137
126
130
131
40
41
47
53
57
76
94
95
96
97
100
101
105
117
120
122
126
132
4.8 * Absolute Stability
4.9 * Establishing Boundedness of Signals
4.10 * Existence and Unicity of Solutions
4.11 Summary
4.12 Notes and References
4.13 Exercises
5. Describing Function Analysis
5.1 Describing Function Fundamentals
5.1.1 An Example of Describing Function Analysis
5.1.2 Applications Domain
5.1.3 Basic Assumptions
5.1.4 Basic Definitions
5.1.5 Computing Describing Functions
165
167
162
164
158
5.2 Common Nonlinearities In Control Systems
5.3 Describing Functions of Common Nonlinearities
5.4 Describing Function Analysis of Nonlinear Systems
5.4.1 The Nyquist Criterion and Its Extension
5.4.2 Existence of Limit Cycles
5.4.3 Stability of Limit Cycles
5.4.4 Reliability of Describing Function Analysis
182
184
180
186
5.5 Summary
5.6 Notes and References
5.7 Exercises
Part II: Nonlinear Control Systems Design
Introduction to Part II
191
6. Feedback Linearization
6.1 Intuitive Concepts
6.1.1 Feedback Linearization And The Canonical Form
6.1.2 Input-State Linearization
6.1.3 Input-Output Linearization
213
216
6.2 Mathematical Tools
6.3
Input-State Linearization of SISO Systems
IX
142
147
151
153
153
154
157
158
169
172
179
187
188
188
191
207
208
229
236
208