Download Brushless Servomotors

Brushless Servomotors
Fundamentals and Applications
EDITED BY
Yasuhiko Dote
Professor, Muroran
Institute of Technology
Japan
and
Sakan Kinoshita
Technical Executive,
Shibaura Seisakusho
Co. Ltd., Japan
CLARENDON PRESS
1990
OXFORD
Contents
xiii
List of contributors
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OUTLINE OF BRUSHLESS SERVOMOTORS
Yasuhiko Dote and Sakan Kinoshita
1
1.0 Introduction
1.1 Operational principles of brushless servomotors
1.2 Brushless servomotors
1.2.1 Brushless d.c. servomotor drive system
1.2.2 DSP controller
1.2.3 Example of a brushless servomotor drive system
Bibliography
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7
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OPERATIONAL PRINCIPLES OF BRUSHLESS
SERVOMOTORS
Shunichi Uchiyama
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2.0
2.1
2.2
2.3
2.4
Introduction
Operational principles of d.c. motors
Operational principles of a.c. motors
Operational principles of brushless servomotors
Brushless servomotor control circuits
2.4.1 Rotor position detector
2.4.2 Sine wave generation circuit
2.4.3 DC-SIN conversion circuit
2.4.4 Sine wave PWM circuit
2.4.5 Speed detector
2.5 Microprocessor-based brushless servomotor control
2.5.1 Rotor position detector and sine wave generation
circuit
2.5.2 Speed control circuit
2.5.3 Current control circuit
2.5.4 PWM circuit
2.5.5 Speed detection circuit
Bibliography
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CONTENTS
STRUCTURE AND MATERIALS OF BRUSHLESS
SERVOMOTORS
Hiroshi Imagawa
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3.0 Introduction
3.1 Brushless servomotor structure
3.1.1 Motor characteristics due to structure
3.1.2 Brushless servomotor components
3.2 Materials and characteristics of permanent magnets
3.2.1 Alnico magnets
3.2.2 Ferrite magnets
3.2.3 Rare-earth cobalt magnets
3.2.4 Neodymium-iron magnets
Bibliography
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BRUSHLESS SERVOMOTOR SENSORS AND DIGITAL
SIGNAL PROCESSORS
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Masateru Nagakura
4.0 Introduction
4.1 Optical encoder
4.1.1 Incremental encoder
4.1.2 Absolute encoder
4.2 Magnetic encoder
4.2.1 Operational principles
4.2.2 Features of magnetic encoders
4.2.3 Considerations in using magnetic encoders
4.3 Considerations in using rotary encoders
4.3.1 Standards for selection of rotary encoders
4.3.2 Output circuits
4.3.3 Wiring of rotary encoders
4.3.4 Considerations in coupling
4.4 Resolver
4.4.1 Detector circuit
4.4.2 Characteristics of resolvers
4.5 Rotary encoder terminology
4.6 Digital signal processors
Bibliography
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MAIN CIRCUIT OF BRUSHLESS SERVOMOTORS
Yasuhiko Dote and Yukio Hashimoto
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5.0 Introduction
5.1 Large power semiconductor devices
5.1.1 Bipolar power transistors
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CONTENTS
6
ix
5.1.2 Large power MOSFET
5.1.3 GTO thyristor
5.1.4 SI thyristor
5.1.5 Insulated gate bipolar transistor
5.1.6 MOS-controlled thyristor
5.1.7 Comparison of modern power semiconductor devices
5.2 Main circuit configuration
5.2.1 Main circuit
5.2.2 Trigger control circuit
5.3 Protection of main circuit
Bibliography
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BRUSHLESS SERVOMOTOR CONTROL
Yasuhiko Dote
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6.0 Introduction to control techniques
6.1 Brushless servomotor control
6.1.1 Control principles of brushless servomotors
6.1.2 Mathematical model for brushless servomotor
drive system
6.2 Motion control
6.2.0 Introduction
6.2.1 Positioning accuracy and speed control rate
6.2.2 Force control and acceleration control
6.2.3 Control considerations in mechanical systems with
non-linearity
6.2.4 Mechanical impedance control
6.2.5 Vibration suppression control
6.2.6 Brushless servomotor current and flux controls
6.3 Digital robust control algorithms
6.3.0 Introduction
6.3.1 Equivalent disturbance observer and zeroing
6.3.2 Improved sliding mode control with variable-gain
feedforward path
6.3.3 Variable-structure PI with variable-gain feedforward,
input modulation and equivalent disturbance observer
6.3.4 Model reference adaptive control
6.3.5 Learning (repetitive) control
6.3.6 Intelligent (expert) control
6.4 Sensors and signal processing
6.4.0 Introduction
6.4.1 High-resolution position-sensing algorithm
6.4.2 High-resolution velocity-sensing algorithms
6.4.3 Disturbance torque observer
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x
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CONTENTS
6.4.4 Discussion on observers
Bibliography
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DESIGN METHOD FOR BRUSHLESS SERVOMOTORS
Haruo Nakatsuka
184
7.0
7.1
7.2
7.3
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Introduction
Torque-generation principles
Motor characteristics
Permanent magnets
7.3.1 Manufacturing process for ferrite magnets
7.3.2 Considerations in using ferrite magnets
7.4 Calculation for magnetic circuit design of permanent-magnet
motors
7.5 Brushless servomotor design
7.6 Performance requirements of servomotors and design
solutions
7.6.1 Usability over wide range of speed control
7.6.2 Quick response to acceleration, deceleration, and
instantaneous reverse rotation
7.6.3 Structure of motors for severe operational conditions
7.6.4 Low vibration and noise
7.6.5 Low rotation ripple and torque ripple
Bibliography
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EXAMPLES OF APPLICATION AND SELECTION OF
BRUSHLESS SERVOMOTORS
Shunichi Uchiyama
8.1 What is the output of a motor?
8.1.1 Calculation of motor output in steady operation
8.1.2 Calculation of motor output necessary for required
acceleration and deceleration
8.1.3 Calculation of motor output with consideration of
duty cycle
8.2 Which to select: d.c. servomotor or a.c. servomotor?
8.3 Servomotor applications
.
8.3.1 Application to industrial robots
8.3.2 X-Y axis feed for precise positioning
8.3.3 Constant-interval table feed for general automated
machines
8.3.4 Radial feed of a forming grinder
8.3.5 X-Y axis operation of an automatic drafting
machine
8.4 Basic terminology for servomotors
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CONTENTS
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MEASUREMENT AND EVALUATION OF BRUSHLESS
SERVOMOTORS
Hitoshi Ishimine
9.1 Torque measurement
9.1.1 Brakes
9.1.2 Torque sensors
9.2 Angular velocity measurement
9.2.1 Methods for measuring angular velocity
9.2.2 Linearity
9.2.3 Symmetry
9.3 Speed fluctuation measurement
9.3.1 Anderson method
9.3.2 Wow and flutter meter method
9.3.3 Fluctuation coefficient method
9.4 Temperature rise
Bibliography
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APPENDIX 1 Derivation of mathematical model for brushless
servomotors
Yasuhiko Dote
APPENDIX 2 Derivation and estimation of mathematical models
(design of a state observer)
APPENDIX 3 Analogy and duality between mechanical systems and
electrical systems
APPENDIX 4 Unit conversions
APPENDIX 5 Types of standards
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Index
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