FUNDAMENTALS of ROBOT TECHNOLOGY An Introduction to Industrial Robots, T eleoperators and Robot Vehicles D J Todd &\ Kogan Page
First published in 1986 by Kogan Page Ltd 120 Pentonville Road, London Nl 9JN Copyright 1986 DJ Todd Softcover reprint of the hardcover lst edition 1986 All rights reserved British library Cataloguing in Publication Data Todd, DJ. Fundamentals of robot technology: an introduction to industrial robots, teleoperators and robot vehicles. 1. Robots, Industrial I. Title 629.8'92 TS191 ISBN-13: 978-94-011-6770-3 e-isbn-13: 978-94-011-6768-0 DOl: 10.1007/978-94-011-6768-0 Anchor Brendon Ltd, Tiptree, Essex
Contents Chapter 1: Introduction Definitions of 'robot' and 'robotics' 10 Other definitions in robotics 10 Connections between robotics and some related subjects 11 Artificial intelligence 11 Flexible manufacturing systems, factory automation, computer-aided manufacturing 12 Bibliographic notes 12 9 Chapter 2: Geometric configurations for robots Introduction 15 The distinction between arms and vehicles 15 Structural elements of manipulators 16 Degrees of freedom and number of joints 16 Types of joint 17 Construction of joints 18 Parallel linkages 18 Constrained linkages 20 Distributed manipulators 20 Robot transporters and workpiece positioners 20 Arm configuations 21 Cartesian 21 Polar 24 Cy lindrical 24 Horizontally jointed arms 24 Vertically jointed or anthropomorphic arms 24 Other arm designs 24 Tension structures 27 Wrists 27 Direct drive to each axis 29 Gear drives 30 Compliance in wrists 32 End effectors (grippers, tools and hands) 33 Two-jaw grippers 34 Special purpose mechanical grippers 35 Vaccum and magnetic grippers 37 Tools 38 Tool and gripper changing 38 Anthropomorphic and other adaptive hands 39 Two dimensional adaptive grippers 40 Anthropomorphic hands 40 Bibliographic notes 42 15 Chapter 3: Operation, programming and control of industrial robots Types of industrial robot and their methods of operation 43 Pick and place manipulators 44 Point to point robots 45 Continuous path robots 45 Methods of teaching and programming 45 Programming pick and place robots 46 43
Chapter 4_- Chapter 5.' Walk-through teaching or pendant teaching 46 Walk-through teaching with path control 47 Lead-through teaching or physical arm leading 48 Off-line programming 48 The implications of sensing for robot control 48 Types of controller and program memory 49 Analysis and control 49 Formulating the kinemati<,: equations 50 Solving the kinematic equations 51 The Jacobian formulation 52 The 'forward' and 'inverse' problems of dynamics 52 Specifying trajectories 52 Servo control of actuators 54 Programming languages for industrial robots 56 Bibliographic notes 57 Actuators for robots Pneumatic actuation 60 Pneumatic valves 62 Hydraulic actuation 63 Hydraulic valves 64 Hydrostatic circuits 65 Hydraulic pumps and associated equipment 65 Electric actuation 69 Direct current servomotors 69 Alternating current servomotors (brushless direct current servomotors) 71 Stepper motors 72 Other electromechanical actuators 73 Mechanical transmission methods 75 Inertia reduction 75 Speed reduction 76 Rotary Irectilinear motion conversion 80 Differentials and parallelogram linkages 80 Bibliographic notes 81 Sensing for robots Joint angle 84 Potentiometers 85 Resolvers and synchros 85 Incremental and absolute encoders (usually optical) 86 J oint angular velocity 87 Rectilinear position 87 Force and torque 88 Strain gauges 88 Piezoelectric force transducers 89 Proximity sensing and range measurement 90 Touch sensing 93 Resistance-based touch sensors 94 Inductance and capacitance 94 Piezoelectric transducers 95 Thermal touch sensing 96 Optical methods of touch sensing 96 Slip 96 Vision 97 Vision hardware 98 Television cameras 98 Illuminator 100 Framestore 100 Preprocessor 101 General purpose computer 101 Types of computer vision 101 Two-dimensional vision with isolated objects and a binary image 102 Stasticial pattern recognition 102 Two-dimensional vision with isolated objects and a grey scale image 103 59 83
Chapter 6: Chapter 7: Touching or overlapping objects 104 Two-dimensional inspection 105 Two-dimensional line tracking 105 Three-dimensional vision: isolated objects 105 Single image (monocular vision) 106 Stereo vision 106 Structured illumination 106 Range imaging 107 Three-dimensional vision applied to a heap of parts 107 Three-dimensional scene analysis for mobile robots 107 Non-visual sensing in welding and other processes 107 Bibliographic notes 108 Performance specifications of industrial robots Geometric configuration; number of axes 110 Positioning accuracy and repeatability 110 Accuracy 110 Repeatability 111 Test methods for accuracy and repeatability 112 Angular accuracy and repeatability 112 Speed 113 Speed and acceleration accuracy 113 Spatial specifications: working volume, swept area, reach 113 Payload (maximum load capacity) 114 Control-related specifications 115 Memory capacity 115 Program structure 115 Advanced features 115 Vibration 116 Miscellaneous specifications 116 Bibliographic notes 116 Applications of industrial robots Machine loading 118 Pallet loading and unloading 120 Investment casting 121 Spot welding 122 Arc welding 123 Spraying (paint, enamel, epoxy resin and other coatings) 126 Fettling (grinding, chiselling); polishing 126 Cutting 127 Inspection 127 Training and education; hobby robots 127 Robots in assembly 130 Typ.:s of robot for assembly 131 Grippers 133 Compliance 136 Design for assembly 136 Part'numbers and types 136 Component design for mechanical handling 137 Design of the assembly process 138 New applications for industrial robots 139 Extension of existing methods to new applications 139 More sensing 140 Artificial intelligence 140 Handling difficult workpieces 140 Integration of industrial robots into the workplace 145 Tracking 145 Work cell configurations 146 Transport of components and assemblies 146 Feeders for assembly robots 147 Control and communication 148 Bibliographic notes 149 109 117
Chapter 8: Teleoperated arms Introduction 151 Methods of contro1151 Mechanical master-slave telemanipulators 151 Powered telemanipulators 152 Servo control of unilateral telemanipulators 152 Bilateral servo manipulators 155 Special characteristics of teleoperators 158 Design criteria for teleoperators 159 Vehicles and transporters 160 Applications of teleoperators 161 Remote handling of radioactive materials 161 Remote handling of explosive and toxic materials 161 Telemanipulation of heavy objects 163 Underwater teleoperation 163 Teleoperation in space and planetary exploration 164 Telemanipulators for the disabled 164 Computer assisted teleoperation 166 Bibliographic notes 170 Chapter 9: Mobile robots Introduction 171 Land surface robots 171 Arrangements of wheels and tracks 171 Unusual wheel and track arrangements 172 Navigation for land vehicles 174 Teleoperation 174 Dead reckoning 175 Inertial navigation 175 Tracking from a fixed base; beacons 175 Satellite navigation 175 Map matching 175 Wall following 176 Route planning 176 Control and communication 176 Sensors for mobile robots 177 Body orientation and angular rates 1 77 Body position, speed and acceleration 177 Terrain scanning 178 Types and applications of mobile robots 179 Education and research 179 Remote handling 183 Military mobile robots 183 Fire-fighting and rescue 187 Construction 188 Mining 188 Planetary exploration 188 Legged robots 188 Comparison of legs and wheels 189 Leg number and arrangement 189 Leg number 189 Leg disposition 190 Relative leg length 190 Leg construction 190 Control 191 Climbing robots 195 Robot submersibles 196 Uses of submersible robots 199 Robots in air and space 201 Space 202 Bibliographic notes 204 Chapter 10: Automated guided vehicles Automated guided vehicle technology 207 Power, steering and guidance 207 151 171 205
Route programming 208 Route planning 210 Loading and unloading 210 Safety; vehicle separation 211 Miscellaneous features 211 Automated guided vehicles with mechanical and optical guidance 211 Free ranging automated guided vehicles 212 Bibliographic notes 213 Chapter 11: Robotics and artificial intelligence Vision 215 Voice communication 216 Planning 21 7 Discrete step planning 218 Route planning 218 Modelling 221 Adaptive control 222 Error monitoring and recovery 222 Autonomy and intelligence in robots 223 Expert systems in robotics 225 Bibliographic notes 226 Chapter 12: Economic and social aspects of robotics Reasons for installing robots 227 Economic costs and benefits of installing industrial robots 228 Safety benefits of using robots 229 Prevention of mechanical damage 229 Avoidance of robot-generated fires and pollution 229 Protection of robots from adverse environments 229 Acceptability of industrial robots by the workforce 230 Employment 231 Other social issues of robotics 231 Social issues 231 Military robotics 232 Police and security uses of mobile robots 232 Teleoperators 232 Medical uses of robots 233 Bibliographic notes 233 References and Bibliography Index 215 227 237 241