1 BASIC CONCEPTS 1
Introduction 1
Control Terminology 1
出版说明 4
序 5
PREFACE 7
Functioning of a Control System 8
Examples of Closed-Loop Control Systems 9
Problems 12
2 BLOCK DIAGRAMS 13
Introduction 13
Definition of a Block Diagram 14
Summing Point 15
Takeoff Point 16
Block Diagram Representation of an Equation 16
Block Diagram Representation of Control Systems 17
General Transfer Function 19
Transfer Functions 19
Transfer Function of a Closed-Loop System 20
Comparison of Positive-Feedback and Negative-Feedback Systems 22
Unity Feedback Systems 28
Conversion to a Unity Feedback System 28
Block Diagram Simplification 29
Op-Amp Simulation of a Block Diagram 34
Summing Point 35
Summing Point with Adjustable SP Input 36
Gain Block 38
Constant-Gain(Noninverting)Block 38
Constant-Gain(Inverting)Block 41
Takeoff Point 41
Summing Point with Multiple Inputs 42
Problems 50
Transformations 54
3 LAPLACE TRANSFORMS 54
Introduction 54
Laplace Transform Integral 55
Transform Notation 56
Rules of Transformation 56
Forward Transformation Procedure 61
Inverse Transformation Procedure 67
Partial-Fraction Expansion 79
Distinct Roots 80
Repeated Roots 81
Applications of Laplace Transforms:Difierential Equations 88
Problems 93
4 MATHEMATICAL MODELING 97
Introduction 97
Mathematical Model 98
Nonlinear Behavior 98
Transfer Functions 99
Electrical Networks 100
Resistor 101
Capacitor 101
Inductor 102
Series RC Circuit 103
Series RL Circuit 105
Series RLC Circuit 107
Mechanical Systems 112
Mass 112
Spring 113
Damper 113
Spring Mass Damper System 114
Analogy Between Physical Systems 116
Fluid Systems 117
Single-Tank Fluid-Level System 117
Two-Tank Fluid-Level System 119
Thermal Systems 122
Heating Systems 123
Problems 124
5 TRANSIENT RESPONSE 127
Introduction 127
Time Response 127
Input Functions 129
Step Function 129
Pulse Function 131
Impulse Function 132
Delayed Impulse Function 133
Ramp Function 134
Sinusoidal Function 134
Types of Transient Responses 135
Overdamped Response 135
Underdamped Response 136
Critically Damped Response 136
Constant Oscillations 137
Increasing Oscillations 137
Exponential Rise 138
Transient Response Through Laplace Transformation 138
Impulse Function Response 144
Characteristic Equation 148
Poles and Zeros of the Transfer Function 151
s-Plane and Pole-Zero Map 153
Pole Location and Transient Response 155
Problems 160
6 FREQUENCY RESPONSE 162
Introduction 162
Methods Used for Frequency Response Representation 164
Frequency Response Determination 166
Problems 186
Introduction 189
7 COMMON TRANSFER FUNCTIONS 189
Common Blocks(Transfer Functions) 191
Constant Block 192
Time Response of a Constant TF 195
Frequency Response of a Constant Block 195
Integral Block 198
Time Response of an Integral Block 198
Frequency Response of an Integral Block 200
Derivative Block 203
Time Response of a Derivative Block 204
Frequency Response of a Derivative Block 204
The Relationship Between Integral and Derivative Blocks 208
First-Order Lag Block 208
Time Response to a Unit Step Input 209
Frequency Response of a First-Order Lag Block 213
First-Order Lead Block 219
Frequency Response of a First-Order Lead Block 220
Time Response to a Unit Step Input 220
Second-Order Lag Block 224
Time Response to a Unit Step Input 225
Characteristics of Underdamped Response 231
Frequency Response of a Second-Order Lag Block 234
Second-Order Lead Block 238
Time Response to a Unit Step Input 240
Frequency Response of a Second-Order Lead Block 240
Dead Time:Transportation Lag Block 241
Time Response to a Unit Step Input 243
Frequency Response of a Dead-Time Block 243
Problems 244
8 STABILITY 248
Introduction 248
Concept of Stability 248
Stability and the Open-Loop Transfer Function 252
Open-Loop Gain and Operating Frequency 255
Stability from a Bode Plot 259
Gain and Phase Margins 261
Gain and Phase Crossover Frequencies 261
Gain Margin(GM) 261
Phase Margin(PM) 263
Desired Gain and Phase Margins 264
Stability from the Characteristic Equation 269
Routh Criterion for Stability 271
Root Locus Analysis 278
Root Locus Through MATLAB 281
Problems 288
9 CONTROLLERS:THE ON-OFF CONTROLLER 291
Introduction 291
Role of a Controller 291
Types of Controllers 292
Use of a Percent as Input and Output 293
Measured Value as a Percentage Value 295
Set Point as a Percentage Value 296
Error as a Percentage Value 296
On-Off Control 298
Types of On-Off Control 298
Electronic Implementation(Analog) 299
Two-Position Control 303
Neutral Zone 304
Controller Action 306
Applications 308
Electronic Implementation 309
Multiposition(Floating)Control 315
Problems 315
Introduction 318
Proportional Controller(P) 318
10 ANALOG CONTROLLER Ⅰ 318
Transfer Characteristic 319
Proportional Band 321
Relationship Between Percent Output and Physical Controller Output 322
Electronic Implementation 326
Frequency Response of a Proportional Controller 332
Proportional Control of a Closed Loop 334
Steady-State Operation with Zero Error 339
Proportional Controller with Offset 346
Offset Voltage Adjustment 346
Integral Controller(Ⅰ) 346
Electronic Implementation 353
Limiting DC Gain 354
Frequency Response of an Ideal Integral Controller 355
Frequency Response of a DC Gain-Limited Integral Controller 356
Derivative Controller(D) 359
Electronic Implementation 365
Frequency Response of a Derivative Controller 366
Limiting High-Frequency Gain 367
Problems 375
11 ANALOG CONTROLLER Ⅱ 378
Introduction 378
Composite Controller Modes 378
Serial Implementation 379
Parallel Implementation 379
PI Controller 380
Electronic Implementation of a PI Controller 383
Frequency Response of a PI Controller 384
PD Controller 391
Electronic Implementation of a PD Controller 393
Frequency Response of a PD Controller 395
PID Controller 400
Electronic Implementation 410
Frequency Response of a PID Controller 412
Changing the Operating Mode 412
Problems 417
12 DIGITAL CONTROLLER 420
Introduction 420
Digital Controller 421
Controller Sequence of Operation 422
Considerations for Digital Control 424
Digital Two-Position Control 426
Sequence of Operation 426
Microcontroller Implementation of a Two-Position Controller 427
Digital PID Controller 433
Analog PID Algorithm 433
Digital PID Algorithm 433
Zero-Order Hold(ZOH) 435
Ideal Digital PID Algorithm 440
Discrete PID Algorithm—BASIC Language 440
Manual Control Mode 442
Velocity Algorithm 443
Improved Derivative Term 444
Microcontroller Implementation of a PID Controller 445
DC Motor Control 445
Control Software Description 448
Problems 453
13 FUZZY CONTROLLER 455
Introduction 455
Continuum World 455
Conventional Logic 457
Fuzzy Logic and Fuzzy Logic Terminology 457
Fuzzy Control System 475
Problem Identification 476
Conceptual Design 476
Problems 487
Introduction 491
14 CONTROLLER TUNING AND SYSTEM DESIGN 491
Controller Tuning 492
Performance Criteria 492
Controller Tuning:Known Plant Model 493
Plant Model from Experimental Response Testing 504
Step Response Test 504
Graphical Analysis 505
Computational Method 508
Frequency Response Test 511
Experimental Determination of Controller Setting 518
Continuous Cycling Method 518
Reaction Curve Method 519
Case Study:Machine Positional Control System 521
Drive Mechanism 522
Position Transducer 522
Problems 530
Feedforward Control 533
15 ADDITIONAL CONTROL TECHNIQUES 533
Introduction 533
Disturbance Signal 534
Ratio Control 537
Cascade Control 537
Autotuning Controller 539
State-Space Techniques 540
State Variables 540
State Equations 540
Transfer Function to State-Space Representation 543
Problems 545
BIBLIOGRAPHY 547
APPENDIX A MATLAB 549
GLOSSARY 559
INDEX 565