383
CHAPTER 11
BASIC CONTROL SYSTEMS DESIGN
William J. Palm III
Department of Mechanical Engineering
University of Rhode Island
Kingston, Rhode Island
1
INTRODUCTION
383
2
CONTROL SYSTEM
STRUCTURE
386
2.1
A Standard Diagram
386
2.2
Transfer Functions
388
2.3
System-Type Number and
Error Coefficients
388
3
TRANSDUCERS AND ERROR
DETECTORS
389
3.1
Displacement and Velocity
Transducers
389
3.2
Temperature Transducers
391
3.3
Flow Transducers
391
3.4
Error Detectors
392
3.5
Dynamic Response of
Sensors
392
4
ACTUATORS
392
4.1
Electromechanical
Actuators
392
4.2
Hydraulic Actuators
394
4.3
Pneumatic Actuators
396
5
CONTROL LAWS
399
5.1
Proportional Control
399
5.2
Integral Control
401
5.3
Proportional-plus-Integral
Control
403
5.4
Derivative Control
404
5.5
PID Control
405
6
CONTROLLER HARDWARE
405
6.1
Feedback Compensation
and Controller Design
405
6.2
Electronic Controllers
406
6.3
Pneumatic Controllers
407
6.4
Hydraulic Controllers
407
7
FURTHER CRITERIA FOR
GAIN SELECTION
409
7.1
Performance Indices
410
7.2
Optimal-Control Methods
411
7.3
The Ziegler–Nichols Rules
412
7.4
Nonlinearities and
Controller Performance
413
7.5
Reset Windup
414
8
COMPENSATION AND
ALTERNATIVE CONTROL
STRUCTURES
414
8.1
Series Compensation
415
8.2
Feedback Compensation
and Cascade Control
415
8.3
Feedforward Compensation
415
8.4
State-Variable Feedback
417
8.5
Pseudoderivative Feedback
418
9
GRAPHICAL DESIGN
METHODS
418
9.1
The Nyquist Stability
Theorem
419
9.2
Systems with Dead-Time
Elements
420
9.3
Open-Loop Design for
PID Control
420
9.4
Design with the Root Locus
421
10 PRINCIPLES OF DIGITAL
CONTROL
424
10.1 Digital Controller Structure
425
10.2 Digital Forms of PID
Control
425
11 UNIQUELY DIGITAL
ALGORITHMS
427
11.1 Digital Feedforward
Compensation
427
11.2 Control Design in the
z-Plane
428
11.3 Direct Design of Digital
Algorithms
432
12 HARDWARE AND
SOFTWARE FOR DIGITAL
CONTROL
433
Revised from William J. Palm III, Modeling, Analysis and Control of Dynamic Systems, 2nd ed., Wiley,
2000, by permission of the publisher.
Mechanical Engine