Feedback Control of Dynamic Systems covers the material that every engineer, and most scientists and prospective managers, needs to know about feedback control–including concepts like stability, tracking, and robustness. Each chapter presents the fundamentals along with comprehensive, worked-out examples, all within a real-world context and with historical background information. The authors also provide case studies with close integration of MATLAB throughout.
An Understandable Introduction to Digital Control
The sections on digital control in Chapters 4, 5, 6, and 7 of the previous edition are now featured solely on a dedicated website for the book (www.FPE7e.com).
Chapter 8 is modified so that it now provides a stand-alone introduction to Digital Control.
For those instructors wanting to include the digital implementation of controllers early in their teaching, the material can be downloaded and used without change from the order that existed in the 6th edition or the students can be directed to the material in Chapter 8.
Real-world Perspective
MATLAB commands are updated throughout the book to utilize the current capabilities of the software.
Keep Your Course Current
A new section on Fundamentals is included in Chapter 1
A new section on Gears is included in Chapter 2
The section on the Laplace transform and frequency response in Chapter 3 is rewritten
A new section on Feedforward Control is included in Chapter 4
The section on PID control in Chapter 4 is rewritten.
The section in Chapter 4 on the effect of zeros on a system is rewritten.
Sections on stability and compensation are rewritten in Chapter 6 for clarity and consistency with current standards in the industry.
An expanded discussion of Nichols plots is included in Chapter 6.
Revised notation of the state-space system from F, G, H, J to A, B, C, D in Chapters 7, 9, & 10.
To prevent any ambiguity, the notation for the compensation was changed from D(s) to Dc(s) throughout the text because of the change in the state-space notation.
The model following procedure is now included in Chapter 7.
Several sections were rewritten in Chapter 8 for clarity.
A new section on the ZOH Equivalent method is included in Chapter 8.
In Chapter 10, the engine control example is updated and the biology example is substantially revised.
Approximately 20% of the Problems in the book are revised or new in all chapters.
~Publisher~
880 p.
24 cm.
ill.
Preface xiii
1 An Overview and Brief History of Feedback Control 1
A Perspective on Feedback Control 1
Chapter Overview 2
1.1 A Simple Feedback System 3
1.2 A First Analysis of Feedback 6
1.3 Feedback System Fundamentals 10
1.4 A Brief History 11
1.5 An Overview of the Book 17
Summary 19
Review Questions 19
Problems 20
2 Dynamic Models 23
A Perspective on Dynamic Models 23
Chapter Overview 24
2.1 Dynamics of Mechanical Systems 24
2.1.1 Translational Motion 24
2.1.2 Rotational Motion 31
2.1.3 Combined Rotation and Translation 39
2.1.4 Complex Mechanical Systems (W)** 42
2.1.5 Distributed Parameter Systems 42
2.1.6 Summary: Developing Equations of Motion
for Rigid Bodies 44
2.2 Models of Electric Circuits 45
2.3 Models of Electromechanical Systems 50
2.3.1 Loudspeakers 50
2.3.2 Motors 52
2.3.3 Gears 56
2.4 Heat and Fluid-Flow Models 57
2.4.1 Heat Flow 58
2.4.2 Incompressible Fluid Flow 61
2.5 Historical Perspective 68
Summary 71
Review Questions 71
Problems 72
3 Dynamic Response 84
A Perspective on System Response 84
Chapter Overview 85
3.1 Review of Laplace Transforms 85
3.1.1 Response by Convolution 86
3.1.2 Transfer Functions and Frequency Response 91
3.1.3 The L− Laplace Transform 101
3.1.4 Properties of Laplace Transforms 103
3.1.5 Inverse Laplace Transform by Partial-Fraction Expansion 105
3.1.6 The Final Value Theorem 107
3.1.7 Using Laplace Transforms to Solve Differential Equations 109
3.1.8 Poles and Zeros 111
3.1.9 Linear System Analysis Using Matlab_ 112
3.2 System Modeling Diagrams 118
3.2.1 The Block Diagram 118
3.2.2 Block-Diagram Reduction Using Matlab 122
3.2.3 Mason’s Rule and the Signal Flow Graph (W) 123
3.3 Effect of Pole Locations 123
3.4 Time-Domain Specifications 131
3.4.1 Rise Time 132
3.4.2 Overshoot and Peak Time 132
3.4.3 Settling Time 134
3.5 Effects of Zeros and Additional Poles 137
3.6 Stability 146
3.6.1 Bounded Input—Bounded Output Stability 147
3.6.2 Stability of LTI Systems 148
3.6.3 Routh’s Stability Criterion 149
3.7 Obtaining Models from Experimental Data: System Identification (W) 156
3.8 Amplitude and Time Scaling (W) 156
3.9 Historical Perspective 156
Summary 157
Review Questions 159
Problems 159
4 A First Analysis of Feedback 180
A Perspective on the Analysis of Feedback 180
Chapter Overview 181
4.1 The Basic Equations of Control 182
4.1.1 Stability 183
4.1.2 Tracking 184
4.1.3 Regulation 185
4.1.4 Sensitivity 186
4.2 Control of Steady-State Error to Polynomial Inputs: System Type 188
4.2.1 System Type for Tracking 189
4.2.2 System Type for Regulation and Disturbance Rejection 194
4.3 The Three-Term Controller: PID Control 196
4.3.1 Proportional Control (P) 196
4.3.2 Integral Control (I) 198
4.3.3 Derivative Control (D) 201
4.3.4 Proportional Plus Integral Control (PI) 201
4.3.5 PID Control 202
4.3.6 Ziegler—Nichols Tuning of the PID Controller 206
4.4 Feedforward Control by Plant Model Inversion 212
4.5 Introduction to Digital Control (W) 214
4.6 Sensitivity of Time Response to Parameter Change (W) 215
4.7 Historical Perspective 217
Summary 217
Review Questions 218
Problems 218
5 The Root-Locus Design Method
A Perspective on the Root-Locus Design Method 234
Chapter Overview 235
5.1 Root Locus of a Basic Feedback System 235
5.2 Guidelines for Determining a Root Locus 240
5.2.1 Rules for Determining a Positive (180æ) Root Locus 242
5.2.2 Summary of the Rules for Determining a Root Locus 248
5.2.3 Selecting the Parameter Value 249
5.3 Selected Illustrative Root Loci 251
5.4 Design Using Dynamic Compensation 264
5.4.1 Design Using Lead Compensation 266
5.4.2 Design Using Lag Compensation 270
5.4.3 Design Using Notch Compensation 272
5.4.4 Analog and Digital Implementations (W) 274
5.5 A Design Example Using the Root Locus 275
5.6 Extensions of the Root-Locus Method 281
5.6.1 Rules for Plotting a Negative (0æ) Root Locus 281
5.6.2 Consideration of Two Parameters 284
5.6.3 Time Delay (W) 286
5.7 Historical Perspective 287
Summary 289
Review Questions 290
Problems 291
6 The Frequency-Response Design Method
A Perspective on the Frequency-Response Design Method 308
Chapter Overview 309
6.1 Frequency Response 309
6.1.1 Bode Plot Techniques 317
6.1.2 Steady-State Errors 330
6.2 Neutral Stability 331
6.3 The Nyquist Stability Criterion 333
6.3.1 The Argument Principle 334
6.3.2 Application of The Argument Principle to Control Design 335
6.4 Stability Margins 348
6.5 Bode’s Gain—Phase Relationship 357
6.6 Closed-Loop Frequency Response 361
6.7 Compensation 363
6.7.1 PD Compensation 363
6.7.2 Lead Compensation (W) 364
6.7.3 PI Compensation 374
6.7.4 Lag Compensation 375
6.7.5 PID Compensation 381
6.7.6 Design Considerations 387
6.7.7 Specifications in Terms of the Sensitivity Function 389
6.7.8 Limitations on Design in Terms of the Sensitivity Function 394
6.8 Time Delay 398
6.8.1 Time Delay via the Nyquist Diagram (W) 400
6.9 Alternative Presentation of Data 400
6.9.1 Nichols Chart 400
6.9.2 The Inverse Nyquist Diagram (W) 404
6.10 Historical Perspective 404
Summary 405
Review Questions 408
Problems 408
7 State-Space Design 433
A Perspective on State-Space Design 433
Chapter Overview 434
7.1 Advantages of State-Space 434
7.2 System Description in State-Space 436
7.3 Block Diagrams and State-Space 442
7.4 Analysis of the State Equations 444
7.4.1 Block Diagrams and Canonical Forms 445
7.4.2 Dynamic Response from the State Equations 457
7.5 Control-Law Design for Full-State Feedback 463
7.5.1 Finding the Control Law 464
7.5.2 Introducing the Reference Input with Full-State Feedback 473
7.6 Selection of Pole Locations for Good Design 477
7.6.1 Dominant Second-Order Poles 477
7.6.2 Symmetric Root Locus (SRL) 479
7.6.3 Comments on the Methods 488
7.7 Estimator Design 489
7.7.1 Full-Order Estimators 489
7.7.2 Reduced-Order Estimators 495
7.7.3 Estimator Pole Selection 499
7.8 Compensator Design: Combined Control Law and Estimator (W) 501
7.9 Introduction of the Reference Input with the Estimator (W) 514
7.9.1 General Structure for the Reference Input 515
7.9.2 Selecting the Gain 524
7.10 Integral Control and Robust Tracking 525
7.10.1 Integral Control 526
7.10.2 Robust Tracking Control: The Error-Space Approach 528
7.10.3 Model-Following Design 539
7.10.4 The Extended Estimator 543
7.11 Loop Transfer Recovery 547
7.12 Direct Design with Rational Transfer Functions 552