Table Of ContentSENSORS
FOR MOBILE
OBOT
T H E O RY A ND A P P L I C A T I ON
H . R. E V E R E TT
This is an unprecedented reference work that compiles into one convenient source
everything the student or experienced developmental engineer needs to know about
the many supporting technologies associated with the rapidly evolving field of
robotics. Presenting the material in a manner which often parallels strategies of
robotic development, Everett provides a comprehensive yet easy-to-understand
explanation of the theory of sensor operation. An objective review of both prototype
and commercially available candidate systems is presented throughout, followed up
with practical lessons learned from actual use on various robotic vehicles. This book
is a must-have for everyone in the robotics research and development community,
be it in industry, government, or academia.
"A timely contribution to the field of mobile robotics, Everett's book is the most
comprehensive survey appearing to date on sensor technology for this domain. His
text serves both as a valuable reference for the experienced roboticist while also
providing a thorough tutorial on the issues and technologies of mobile sensing for
the novitiate."
—Professor Ron Arkin
Director, Mobile Robot Laboratory
Georgia Institute of Technology, Atlanta, GA
"Sensors for Mobile Robots is the most comprehensive, most meticulously researched,
and most authoritative book in the emerging field of mobile robotics, equally
valuable for experimentalists and theoreticians alike."
—Professor Johann Borenstein
Head, MEAM Mobile Robotics Laboratory
University of Michigan, Ann Arbor, Ml
" In my opinion this book is the definitive work on the subject and is destined to
become a classic."
—Professor H.R. Luxenberg ,
Professor Emeritus, Computer Science Department
California State University, Chico, CA
"This is, simply, an astounding work, in both the range and depth of its coverage."
—Nuts & Volts Magazine, May 1995
"Sensors for Mobile Robots is the right book at the right time for anyone involved
or interested in the rapidly expanding field of mobile robotics or industrial automation.
Everett has provided both the breadth and the depth to enlighten designers with
new ideas, as well as point them to commercial sources of potential solutions for
the plethora of perception problems facing autonomous machines."
—SENSORS Magazine, June 1995
Book Review by Anita Flynn
MIT Artificial Intelligence Laboratory
Massachusetts Institute of Technology
Cambridge, MA
Cover photograph:
ROBARTII. A second generation security
robot employing 132 external sensors
9 781568 810485 >
A K Peters, Ltd.
ISBN l-5bflfll-046-2
Sensors
for Mobile
Robots
Theory and Application
H.R. Everett
Naval Command, Control and
Ocean Surveillance Center
San Diego, California
A K Peters, Ltd.
Wellesley, Massachusetts
Editorial, Sales, and Customer Service Office
A K Peters, Ltd.
289 Linden Street
Wellesley, MA 02181
Copyright © 1995 by A K Peters, Ltd.
All rights reserved. No part of the material protected by this copyright notice may
be reproduced or utilized in any form, electronic or mechanical, including photo-
copying, recording, or by any information storage and retrieval system, without
written permission from the copyright owner.
Library of Congress Cataloging-in-Publication Data
Everett, H. R., 1949-
Sensors for mobile robots : theory and application / H.R. Everett.
p. cm.
Includes bibliographical references and index.
ISBN 1-56881-048-2
1. Mobile robots. 2. Robots—Control systems. I. Title.
TJ211.415.E83 1995
629.8 ' 92—dc20 95-17178
CIP
Many of the designations used by manufacturers and sellers to distinguish their products are
claimed as trademarks. Where designations appear in this book and A K Peters was aware of the
trademark claim, the designations have been printed in italics. Where designations have not been
provided, every effort has been made to ensure accurate presentation of product names and
specifics.
Principle illustrator: Todd Ashley Everett
Printed in the United States of America
99 98 97 96 95 10 9 8 7 6 5 4 3 2 1
Table of Contents
FOREWORD xiii
PREFACE xv
ACKNOWLEDGMENTS xvii
1. INTRODUCTION 1
1.1 DESIGN CONSIDERATIONS 2
1.2 THE ROBOTS 4
1.2.1 WALTER (1965-1967) 4
1.2.2 CRAWLER I (1966-1968) 7
1.2.3 CRAWLER II (1968-1971) 10
1.2.4 ROBARTI (1980-1985) 11
1.2.5 ROBART 11(1982-) 15
1.2.6 MODBOT(1990-) 17
1.2.7 USMC TeleOperated Vehicle (1985-1989) 19
1.2.8 MDARS Interior (1989-) 22
1.2.9 Surrogate Teleoperated Vehicle (1990-1993) 25
1.2.10 ROBART 111(1992-) 28
1.2.11 MDARS Exterior (1994-) 31
1.3 REFERENCES 33
2. DEAD RECKONING 35
2.1 ODOMETRY SENSORS 36
2.1.1 Potentiometers 36
2.1.2 Synchros and Resolvers 38
2.1.3 Optical Encoders 41
2.2 DOPPLER AND INERTIAL NAVIGATION 45
2.2.1 Doppler Navigation 45
2.2.2 Inertial Navigation 47
2.3 TYPICAL MOBILITY CONFIGURATIONS 48
2.3.1 Differential Steering 49
2.3.2 Ackerman Steering 55
2.3.3 Synchro Drive 57
2.3.4 Tricycle Drive 61
2.3.5 Omni-Directional Drive 61
2.4 INTERNAL POSITION ERROR CORRECTION 63
2.5 REFERENCES 65
3. TACTILE AND PROXIMITY SENSING 69
3.1 TACTILE SENSORS 69
3.1.1 Tactile Feelers 69
3.1.2 Tactile Bumpers 71
3.1.3 Distributed Surface Arrays 75
vi Sensors for Mobile Robots
3.2 PROXIMITY SENSORS 75
3.2.1 Magnetic Proximity Sensors 76
3.2.2 Inductive Proximity Sensors 86
3.2.3 Capacitive Proximity Sensors 90
3.2.4 Ultrasonic Proximity Sensors 91
3.2.5 Microwave Proximity Sensors 92
3.2.6 Optical Proximity Sensors 93
3.3 REFERENCES 98
4. TRIANGULATION RANGING 103
4.1 STEREO DISPARITY 106
4.1.1 JPL Stereo Vision 109
4.1.2 David Sarnoff Stereo Vision Ill
4.2 ACTIVE TRIANGULATION 114
4.2.1 Hamamatsu Rangefinder Chip Set 116
4.2.2 Draper Laboratory Rangefinder 117
4.2.3 Quantic Ranging System 119
4.3 ACTIVE STEREOSCOPIC 121
4.3.1 HERMIES 122
4.3.2 Dual-Aperture 3-D Range Sensor 124
4.4 STRUCTURED LIGHT 125
4.4.1 TRC Strobed-Light Triangulation System 127
4.5 KNOWN TARGET SIZE 128
4.5.1 NAMCO Lasernet8 Scanning Laser Sensor 129
4.6 OPTICAL FLOW 131
4.6.1 NIST Passive Ranging and Collision Avoidance 133
4.6.2 David Sarnoff Passive Vision 133
4.7 REFERENCES 134
5. TIME OF FLIGHT 139
5.1 ULTRASONIC TOF SYSTEMS 141
5.1.1 National Semiconductor's LM1812 Ultrasonic Transceiver 141
5.1.2 Massa Products Ultrasonic Ranging Module Subsystems 143
5.1.3 Polaroid Ultrasonic Ranging Modules 144
5.1.4 Cybermotion CA-2 Collision Avoidance System 148
5.2 LASER-BASED TOF SYSTEMS 150
5.2.1 Schwartz Electro-Optics Laser Rangefinders 150
5.2.2 RIEGL Laser Measurement Systems 158
5.2.3 Odetics Fast Frame Rate 3-D Laser Imaging System 161
5.2.4 RVSI Long Optical Ranging and Detection System 162
5.3 REFERENCES 165
6. PHASE-SHIFT MEASUREMENT AND FREQUENCY MODULATION 169
6.1 PHASE-SHIFT MEASUREMENT 169
6.1.1 ERIM 3-D Vision Systems 174
6.1.2PerceptronLASAR 177
6.1.3 Odetics Scanning Laser Imaging System 178
6.1.4 Sandia Scannerless Range Imager 180
6.1.5 ESP Optical Ranging System 183
6.1.6 Acuity Research AccuRange 3000 185
Table of Contents vii
6.1.7 TRC Light Direction and Ranging System 187
6.2 FREQUENCY MODULATION 188
6.2.1 VRSS Automotive Collision Avoidance Radar 190
6.2.2 VORAD Vehicle Detection and Driver Alert System 191
6.2.3 Safety First Systems Vehicular Obstacle Detection and Warning System 193
6.2.4 Millitech Millimeter Wave Radar 194
6.3 REFERENCES 197
7. OTHER RANGING TECHNIQUES 199
7.1INTERFEROMETRY 199
7.1.1 CLS Coordinate Measuring System 201
7.2 RANGE FROM FOCUS 202
7.2.1 Honeywell Autofocus Systems 203
7.2.2 Associates and Ferren Swept-Focus Ranging 206
7.2.3 JPL Range-from-Focus System 210
7.3 RETURN SIGNAL INTENSITY 211
7.3.1 Programmable Near-Infrared Proximity Sensor 212
7.3.2 Australian National University Rangefinder 215
7.3.3 MIT Near-Infrared Ranging System 216
7.3.4 Honeywell Displaced-Sensor Ranging Unit 216
7.4 REFERENCES 217
8. ACOUSTICAL ENERGY 221
8.1 APPLICATIONS 224
8.2 PERFORMANCE FACTORS 225
8.2.1 Atmospheric Attenuation 225
8.2.2 Target Reflectivity 227
8.2.3 Air Turbulence 232
8.2.4 Temperature 233
8.2.5 Beam Geometry 234
8.2.6 Noise 239
8.2.7 System-Specific Anomalies 240
8.3 CHOOSING AN OPERATING FREQUENCY 242
8.4 SENSOR SELECTION CASE STUDY 242
8.5 REFERENCES 244
9. ELECTROMAGNETIC ENERGY 249
9.1 OPTICAL ENERGY 252
9.1.1 Electro-Optical Sources 253
9.1.2 Performance Factors 258
9.1.3 Choosing an Operating Wavelength 262
9.2 MICROWAVE RADAR 263
9.2.1 Applications 264
9.2.2 Performance Factors 264
9.3 MILLIMETER-WAVE RADAR 267
9.3.1 Applications 268
9.3.2 Performance Factors 269
9.3.3 Choosing an Operating Frequency 274
9.4 REFERENCES 274
viii Sensors for Mobile Robots
10. COLLISION AVOIDANCE 279
10.1 NAVIGATIONAL CONTROL STRATEGIES 279
10.1.1 Reactive Control 280
10.1.2 Representational World Modeling 290
10.1.3 Combined Approach 295
10.2 EXTERIOR APPLICATION CONSIDERATIONS 299
10.3 NAVIGATIONAL RE-REFERENCING 301
10.4 REFERENCES 302
11. GUIDEPATH FOLLOWING 305
11.1 WIRE GUIDED 306
11.2 OPTICAL STRIPE 309
11.2.1 ModBot Optical Stripe Tracker 310
11.2.2 U/V Stimulated Emission 312
11.3 MAGNETIC TAPE 313
11.3.1 Macome Magnetic Stripe Follower 314
11.3.2 Apogee Magnetic Stripe Follower 315
11.3.3 3M/Honeywell Magnetic Lateral Guidance System 316
11.4 HEAT AND ODOR SENSING 317
11.5 INTERMITTENT-PATH NAVIGATION 321
11.5.1 MDARS Interior Hybrid Navigation 322
11.5.2 Free Ranging On Grid 322
11.6 REFERENCES 325
12. MAGNETIC COMPASSES 327
12.1 MECHANICAL MAGNETIC COMPASSES 328
12.1.1 Dinsmore Starguide Magnetic Compass 329
12.2 FLUXGATE COMPASSES 330
12.2.1 Zemco Fluxgate Compasses 337
12.2.2 Watson Gyro Compass 340
12.2.3 KVH Fluxgate Compasses 341
12.2.4 Applied Physics Systems Miniature Orientation Sensor _ 343
12.3 MAGNETOINDUCTIVE MAGNETOMETERS 344
12.3.1 Precision Navigation TCM Magnetoinductive Compass 345
12.4 HALL-EFFECT COMPASSES 347
12.5 MAGNETORESISTIVE COMPASSES 349
12.5.1 Philips AMR Compass 350
12.5.2 Space Electronics AMR Compass 351
12.5.3 Honeywell HMR Series Smart Digital Magnetometer 352
12.6 MAGNETOELASTIC COMPASSES 353
12.7 REFERENCES 357
13. GYROSCOPES 361
13.1 MECHANICAL GYROSCOPES 362
13.1.1 Space-Stable Gyroscopes 362
13.1.2 Gyrocompasses 364
13.1.3 Rate Gyros 365
Table of Contents ix
13.2 OPTICAL GYROSCOPES 371
13.2.1 Active Ring-Laser Gyros 373
13.2.2 Passive Ring Resonator Gyros 380
13.2.3 Open-Loop Interferometric Fiber-Optic Gyros 381
13.2.4 Closed-Loop Interferometric Fiber-Op tic Gyros 387
13.2.5 Resonant Fiber-Optic Gyros 389
13.3 REFERENCES 390
14. RF POSITION-LOCATION SYSTEMS 395
14.1 GROUND-BASED RF SYSTEMS 395
14.1.1 Loran 395
14.1.2 Kaman Sciences Radio Frequency Navigation Grid 396
14.1.3 Precision Technology Tracking and Telemetry System 398
14.1.4 Motorola Mini-Ranger Falcon 400
14.1.5 Harris Infogeometric System 401
14.2 SATELLITE-BASED SYSTEMS 403
14.2.1 Transit Satellite Navigation System 403
14.2.2 Navstar Global Positioning System 405
14.3 REFERENCES 420
15. ULTRASONIC AND OPTICAL POSITION-LOCATION SYSTEMS 423
15.1 ULTRASONIC POSITION-LOCATION SYSTEMS 423
15.1.1 Ultrasonic Transponder Trilateration 424
15.1.2 Ultrasonic Signature Matching 431
15.2 OPTICAL POSITION-LOCATION SYSTEMS 433
15.2.1 CRAWLER I Homing Beacon 433
15.2.2 ROBART II Recharging Beacon 434
15.2.3 Cybermotion Docking Beacon 436
15.2.4 Hilare 438
15.2.5 NAMCO Laserneta Scanning Laser Sensor 439
15.2.6 Caterpillar Self-Guided Vehicle 441
15.2.7 TRC Beacon Navigation System 442
15.2.8 Intelligent Solutions EZNav Position Sensor 442
15.2.9 Imperial College Beacon Navigation System 444
15.2.10 MTI Research CON AC 445
15.2.11 MDARS Lateral-Post Sensor 448
15.3 REFERENCES 452
16. WALL, DOORWAY, AND CEILING REFERENCING 455
16.1 WALL REFERENCING 455
16.1.1 Tactile Wall Referencing 455
16.1.2 Non-Contact Wall Referencing 458
16.1.3 Wall Following 461
16.2 DOORWAY TRANSIT REFERENCING 465
16.3 CEILING REFERENCING 472
16.3.1 Polarized Optical Heading Reference 472
16.3.2 Georgia Tech Ceiling Referencing System 473
16.3.3 TRC HelpMate Ceiling Referencing System 474
16.3.4 MDARS Overhead-Beam Referencing System 476
16.4 REFERENCES 477
x Sensors for Mobile Robots
17. APPLICATION-SPECIFIC MISSION SENSORS 479
17.1 THE SECURITY APPLICATION 479
17.1.1 Acoustical Detection 480
17.1.2 Vibration Sensors 484
17.1.3 Ultrasonic Presence Sensors 484
17.1.4 Optical Motion Detection 485
17.1.5 Passive Infrared Motion Detection 486
17.1.6 Microwave Motion Detection 493
17.1.7 Video Motion Detection 494
17.1.8 Intrusion Detection on the Move 496
17.1.9 Verification and Assessment 502
17.2 AUTOMATED INVENTORY ASSESSMENT 504
17.2.1 MDARS Product Assessment System 505
17.3 REFERENCES 510
APPENDIX 513
INDEX 523
