DC Servo Systems Defined
Scope and Definition
The Concept of Feedback Control
Types of Control
Comments on Motion Control
Introduction to a DC Motor Driving a Mechanical Load
Realization of a Velocity Servo
Anatomy of a Continuous-Time DC Servo
Description
Intended Use
The Prototype
Electrical Design and Construction
Mechanical Design and Construction
Parts List
The Prototype as a Control System
Block Diagram Representations
Electrical Schematic Walk-Through
DC Motors in Servo Systems
Operational Principles
Basic Classes of DC Motors
Considerations in Motor Selection
Procedure for Meeting a Design Goal
Mathematical Modeling of DC Motors and Transmissions
Direct-Drive Model
Motor and Gear Train Model
Feedback Control Systems
Mathematical Notation
Linear, Time-Invariant Systems
Oscillations, Rotating Vectors, and the Complex Plane
From Fourier series to Laplace Transform
Elementary Laplace Transforms
System Analysis Using Laplace Transforms
Philosophy of Feedback Control
Accuracy of Feedback Systems
Stability Assessment—the Root-Locus Method
Proportional Control of a Second-Order DC Servo
Proportional Control
Second-Order Approximation
Basic Approach
Transfer Function Development
Response to a Step-Input Command
Response to a Ramp-Input Command
Response to a Sinusoidal-Input Command
Compensation of a Continuous-Time DC Servo
Compensation Using Derivative Control
Compensation Using Integral Control
Compensation Using Derivative and Integral Control
Tools for Predicting Performance
Overall Compensation Strategy
Op-Amps and Control Systems
Compensation by Theoretical Prediction
DC Servo Amplifiers and Shaft Encoders
DC Servo Amplifiers
PWM Switch-Mode Amplifiers
Sign/Magnitude Control with the LMD18200
Voltage Source versus Current Source
Shaft Encoders
Control of a Position Servo Using a PIC Microcontroller
Initial Motor Selection
Setting the Move Requirements
Hardware and Software Development
Appendix
Biography
Stephen M. Tobin is the founder and president of Optical Tools Corporation. He received his B.S. degree in Mechanical Engineering from the University of New Hampshire in 1983. He spent the first five years of his career in the motion control field, working in step motor and optical encoder design engineering with divisions of Allied-Signal and Dresser Industries. He then turned his attention to the development of electro-optical instrumentation. He joined General Eastern Instruments (now a division of General Electric) in 1988, working on closed-loop optical humidity measurement systems. While employed at General Eastern, he earned his M.S. degree in electrical engineering with a concentration in electro-optics from Tufts University in 1994. He later spent six years developing medical devices at Arthur D. Little, a world-renowned consulting firm based in Cambridge, Massachusetts. Motion control continues to be a lifelong passion for Mr. Tobin, who founded Optical Tools Corporation in 2004 and continues to consult for the medical device and manufacturing automation communities. He holds four U.S. patents and is a member of the Tau Beta Pi National Engineering Honor Society.
