Electromechanical Motion Systems

Acknowledgements xiii
1 Introduction 1
1.1 Targeted Readership 2
1.2 Motion System History 2
1.3 Suggested Library for Motion System Design 5
Reference 6
2 Control Theory Overview 7
2.1 Classic Differential/Integral Equation Approach 7
2.2 LaPlace Transform-the S Domain 10
2.3 The Transfer Function 13
2.4 Open versus Closed Loop Control 15
2.5 Stability 22
2.6 Basic Mechanical and Electrical Systems 23
2.7 Sampled Data Systems/Digital Control 28
References 34
3 System Components 35
3.1 Motors and Amplifiers 35
3.2 Gearheads 107
3.3 Leadscrews and Ballscrews 119
3.4 Belt and Pulley 126
3.5 Rack and Pinion 129
3.6 Clutches and Brakes 132
3.7 Servo Couplings 140
3.8 Feedback Devices 146
References 164
Additional Readings 165
4 System Design 167
4.1 Position, Velocity, Acceleration, Jerk, Resolution,Accuracy, Repeatability 167
4.2 Three Basic Loops - Current/Voltage, Velocity,Position 170
4.3 The Velocity Profile 182
4.4 Feed Forward 195
4.5 Inertia 200
4.6 Shaft Compliance 210
4.7 Compensation 216
4.8 Nonlinear Effects 224
4.9 The Eight Basic Building Blocks 230
References 253
5 System Examples - Design and Simulation 255
5.1 Linear Motor Drive 255
5.2 Print Cylinder Control 257
5.3 Conveyor System - Clutch/Brake Control 261
5.4 Bang-Bang Servo (Slack Loop System) 267
5.5 Wafer Spinner 272
Appendix 275
A.1 Brushless Motor Speed/Torque Curves 275
A.2 Inertia Calculation - Excel Program 277
A.3 Time Constants versus Viscous Damping Constant 277
A.4 Current Drive Review 279
A.5 Conversion Factors 285
A.6 Work and Power 286
A.7 I2R Losses 287
A.8 Copper Resistivity 290
Index 291