Control Systems Laboratory


by Stephen Yurkovich, Kendall-Hunt Publishing Company, 1991.

Table of Contents

Preface

Lab #1 Instrumentation and Software

OBJECTIVE
DISCUSSION: Computer and GPIB
DISCUSSION: Instrumentation
DISCUSSION: Software
DISCUSSION: Important Procedures
A. Measuring Voltage and Time Using Cursor Function
B. Displaying Measurements on the Digital Oscilloscope
C. Display Dumping from DO to HPGL Plotter
D. Waveform Acquire Using EZTEST
E. Computer Control of Instruments
F. MATRIXx Essentials
PROCEDURE
EXERCISES
LAB #1 APPENDIX

Lab #2 Analog Simulation
OBJECTIVE
DISCUSSION
A. Simulation
B. Operational Amplifiers
C. Damping
D. Frequency Response over the GPIB
PROCEDURE
EXERCISES

Lab #3 Gain Compensation and Feedback
OBJECTIVE
DISCUSSION
A. Root Locus Design
B. Bode Design
C. The FEEDBACK Connection Command in MATRIXx
PROCEDURE
EXERCISES

Lab #4 Lag Compensation
OBJECTIVE
DISCUSSION
A. Overview
B. Bode Design
C. Root Locus Design
PROCEDURE
EXERCISES
Lab #5 Lead Compensation

OBJECTIVE
DISCUSSION
A. Overview
B. Bode Design
C. Root Locus Design
PROCEDURE
EXERCISES

Lab #6 Tuning an Analog PID Controller
OBJECTIVE
DISCUSSION
A. Overview
B. Tuning Rules
C. Implementation
PROCEDURE
EXERCISES

Lab #7 Discrete-Time System Simulation
OBJECTIVE
DISCUSSION
A. Overview
B. The Z-Plane
C. Discrete Equivalents
D. Hardware Characteristics
PROCEDURE
EXERCISES

Lab #8 Compensation for Sampled Data Systems
OBJECTIVE
DISCUSSION
A. Design by Discrete Equivalent
B. Direct Discrete Design
C. MATRIXx for Discrete-Time Systems
PROCEDURE
EXERCISES

Lab #9 Tuning a Digital PID Controller
OBJECTIVE
DISCUSSION
A. Overview
B. Tuning Rules
C. Some MATRIXx Hints
PROCEDURE
EXERCISES

Index

Preface

This book is intended as a manual for a one term laboratory course in control systems. The only prerequisite for the book is a standard undergraduate course sequence in signals and systems. It is generally not necessary for the user to have had a course in control systems per se, though it is perhaps useful to have an understanding of some of the basic fundamental concepts useful in control theory, such as feedback, frequency response, root locus analysis, block diagrams, closed-loop stability, and so on. While sections of each chapter (Lab) overview some of the technical details of the fundamental concepts involved, the coverage is not intended to be complete. Rather, it is expected that the student treat the technical development as review, or to supplement with outside reading when necessary.

The first version of this book was written in 1990 while I was developing the laboratory course at Ohio State with funding from the National Science Foundation (Instrumentation and Laboratory Improvement Program) and an equipment donation from the Textronix Corporation. As the course is taught now, juniors spend four hours per week in the laboratory for ten weeks. With this much exposure, in a ten week quarter the entire sequence of nine Labs is easily covered. Typically the tenth week is reserved for a "lab practical'' examination, testing the students' understanding of analysis and design procedures which exercise the instrumentation and software. Clearly, the manual as written could be used in a similar fashion (where, for example, the instructor could pick and choose a subset of Labs to cover) for a semester course in Control Systems which has an accompanying laboratory component; as a matter of fact, I believe that is where it would be best applied.

A feature of the laboratory course is the utilization of computer-controlled instrumentation over the GPIB. Although only the first few Labs make explicit use of this feature, it is expected that the students continue throughout the course to use the tools developed early on for analysis and design. Another important feature is the use of a commercially available software package for computer-aided analysis and design. Finally, the introduction of concepts from sampled-data systems and digital control broadens the scope and treatment of the course material.

A characteristic immediately evident in each of the Labs is that none involve "real'' physical plants such as a motor or heater, although each does involve an analog plant in the form of an operational amplifier circuit. There are basically two reasons for this: 1) I wanted to keep the nature of each Lab as generic as possible; thus, a ``real plant'' could be substituted, without any loss of continuity, in most of the procedures. 2) As taught currently at Ohio State, many students move on to take an advanced digital control laboratory course, on the same hardware, which involves physical plants such as motors, heaters, level tanks, and so on.

The specific instrumentation, hardware components, and software packages employed in the course, and therefore emphasized herein, are, I believe, general purpose enough to make this book useful in a variety of laboratory situations. I would, in fact, be pleased to share my experiences in the ongoing process of laboratory development with the interested instructor, particularly with regard to the structure and content of this book. For instance, I will gladly share any of the various software routines discussed herein, such as the GPIB interfacing routines GAIN and PHASE, the digital filter program SAMPLE which accesses the data acquisition hardware, and so on.

It is my pleasure to acknowledge several people who were instrumental in the development of the book material and laboratory. To my graduate students Anthony P. Tzes, Man-Fung Cheung and Sotirios Gyftakis I owe a debt of gratitude. Moreover, I thank Professor Robert J. Mayhan for his support and encouragement in the project, and Professor Kevin M. Passino for valuable suggestions in proofreading. Final production of the manuscript was made possible with help from Bruce O'Keefe who prepared several of the figures, and the diligent typing of Michelle Jurcenko who prepared the original drafts for the course.

Stephen Yurkovich
May 1991

Prepared: March 1995