B
uild Your Own
Combat Robot
Pete Miles
Tom Carroll
McGraw-Hill/Osborne
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DOI: 10.1036/007222844X
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CONTENTS AT A GLANCE
1
Welcome to Competition Robots
1
2
Getting Started
21
3
Robot Locomotion
41
4
Motor Selection and Performance
61
5
It’s All About Power
79
6
Power Transmission: Getting Power to Your Wheels
103
7
Controlling Your Motors
127
8
Remotely Controlling Your Robot
157
9
Robot Material and Construction Techniques
183
10
Weapons Systems for Your Robot
203
11
Autonomous Robots
239
12
Robot Brains
259
13
Robot Sumo
275
14
Real-Life Robots: Lessons from Veteran Builders
305
15
Afterword
329
A
Prototyping Electronics
335
B
Resources and References
343
C
Helpful Formulas
355
Index
358
iii
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Contents
ACKNOWLEDGMENTS,
INTRODUCTION,
1
XI
XIII
Welcome to Competition Robots
What Is a Robot?,
1
5
Combat Robot Competitions,
BattleBots,
5
7
Robot Wars,
9
BotBash,
11
Robotica,
13
FIRST (For Inspiration and Recognition of Science
and Technology), 14
Robot Soccer,
16
The Scope of This Book,
2
17
Getting Started
21
The Robot Design Approach,
23
The Game of Compromise,
Design for Maintenance,
Start Building Now,
29
31
33
Testing, Testing, Testing,
34
Top Ten Reasons Why a Robot Fails,
Sources of Robot Parts,
34
35
Cost Factors in Large Robot Construction,
Safety,
Safety in the Use of Shop Tools,
Safety with Your Robot,
3
35
36
37
37
Robot Locomotion
Robots with Legs,
41
42
Tank Treads: The Power of a Caterpillar Bulldozer in a Robot,
Building Tank Treads for a Robot,
Wheels: A Tried and True Method of Locomotion,
Types of Steering,
47
47
Wheel Configurations,
50
Selecting Wheels for Your Combat Robot,
Tires,
45
46
51
53
Mounting and Supporting the Wheels and Axles,
Wheel Drive Types,
54
57
Protecting Your Robot’s Wheels,
59
Copyright 2002 by The McGraw-Hill Companies, Inc. Click Here for Terms of Use.
v
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Build Your Own Combat Robot
4
Motor Selection and Performance
Electric Motor Basics,
Determining the Motor Constants,
Power and Heat,
Motor Sources,
73
74
Internal Combustion Engines,
5
67
68
High-Performance Motors,
Conclusion,
61
62
76
77
It’s All About Power
Battery Power Requirements,
79
80
Measuring Current Draw from the Battery,
Battery Capacity Basics,
80
83
Preventing Early Battery Death,
84
Sizing for a 6-Minute Run Time,
85
Comparing SLA, NiCad, and NiMH Run-Time Capacities,
Electrical Wiring Requirements,
Battery Types,
91
92
Sealed Lead Acid,
93
Nickel Cadmium (NiCad),
95
Nickel Metal Hydride (NiMH),
Alkaline,
97
98
Lithium Ion,
99
Installing the Batteries: Accessible vs. Nonaccessible,
6
100
Power Transmission: Getting Power to Your Wheels
Power Transmission Basics,
Torque,
Force,
109
109
Mounting the Motors,
Methods of Power Transmission,
Chain Drive Systems,
Chain Sprockets,
Flat Belts,
115
117
118
118
Synchronous Belts,
V-Belts,
113
114
115
Buying the Chain,
Belt Drive Systems,
112
112
Thermal Considerations for the Motor,
Gearboxes,
103
106
Location of the Locomotion Components,
119
121
122
Mounting Gear Assemblies,
Securing Gears to Shafts,
7
86
122
122
Controlling Your Motors
Relay Control,
128
Poles and Throws,
128
127
Contents
Current Ratings,
129
How It All Works Together,
Variable Speed Control Basics,
132
139
Controlling Speed = Controlling Voltage,
Commercial Electronic Speed Controllers,
8
140
143
Remotely Controlling Your Robot
Traditional R/C Controls,
The R/C Controller’s Interface,
The R/C Servo,
Control Channels,
157
158
159
160
160
Radio Control Frequencies,
162
AM, FM, PCM, and Radio Interference,
Amplitude Modulation,
167
Frequency Modulation,
167
167
Radio Interference and Reliable Control,
Radio to Radio Interference,
Antennas and Shielding,
170
172
173
Antenna Placement,
174
Innovation First Isaac Robot Controller and Other Radio Modems,
Radio Modems,
Failsafe Compliance,
9
179
Robot Material and Construction Techniques
Metals and Materials,
184
185
General Machining Operations,
193
Tools You Might Need to Construct Robots,
Welding, Joining, and Fastening,
When in Doubt, Build It Stout,
195
201
Weapons Systems for Your Robot
Weapon Strategy and Effectiveness,
Ram Bots,
205
Wedge Bots,
208
Lifter Bots,
210
Launchers,
212
Clamp Bots,
215
Thwack Bots,
217
Overhead Thwack Bots,
Spinner Bots,
Saw Bots,
220
222
Vertical Spinner,
Drum Bots,
224
226
Hammer Bots,
228
193
195
Structural Design for Fastener Placement,
10
183
184
High-Strength Plastics,
Metals,
175
178
219
204
203
vii
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Build Your Own Combat Robot
Crusher Bots,
Spear Bots,
231
233
Closing Remarks on Weapons,
11
236
Autonomous Robots
239
Using Sensors to Allow Your Robot to See, Hear, and Feel,
Passive Sensors,
Active Sensors,
243
Thermal Sensors,
Tilt Sensors,
241
242
246
247
Bump Sensors,
248
Implementing Sensors in Combat Robots,
248
Sensing: It’s a Noisy World Out There,
Techniques for Improving Sensor Input,
249
249
Semiautonomous Target and Weapon Tracking,
Semiautonomous Weapons,
250
251
Implementing Semiautonomous Target Tracking,
251
Semiautonomous Target Tracking with
Constant Standoff Distances, 252
Autonomous Target Tracking,
253
Fully Autonomous Robot Class,
More Information,
12
253
257
Robot Brains
259
Microcontroller Basics,
Basic Stamp,
BrainStem,
266
Handy Board,
BotBoard,
260
264
267
267
Other Microcontrollers,
267
Microcontroller Applications,
268
The Robo-Goose,
268
The BrainStem Bug,
270
1BDI, an Autonomous Robot,
271
The Rover, Teleoperated with Feedback,
Summary,
13
272
273
Robot Sumo
275
How a Sumo Match Proceeds,
The Sumo Ring Specification,
Mini Sumo,
278
280
281
Modifying an R/C Servo for Continuous Rotation,
Building a Mini Sumo,
284
Mini Sumo Body Assembly,
284
Remote-Control Mini Sumo, 285
Autonomous Mini Sumo, 286
Edge Detector, 286
281
Contents
Object Detector, 290
Sensor Integration, 293
Performance Improvements, 297
Various Mini Sumo Robots, 297
International Robot Sumo Class,
299
Motors, 299
Motor Controllers, 299
Ultrasonic Range Detectors, 300
Infrared Range Detectors, 301
Laser Range Finding and Vision Systems, 301
Advanced Software Algorithms, 301
Traction Improvements, 302
Robot Part Suppliers, 302
Annual Robot Sumo Events,
14
303
Real-Life Robots: Lessons from Veteran Builders
Ronni Katz—Building Chew Toy,
Step 1: Research,
306
Step 2: Conception,
308
Step 3: Building the Bot,
310
Step 4: Creating Weapons and Armor,
Final Words,
311
315
Pete Miles—Building Live Wires,
316
Step 1: Making the Sketch,
316
Step 2: Securing the Motors,
Step 3: Adding Wheels,
316
317
Step 4: Adding Motor Housings and Controllers,
Step 5: Layout and Modeling,
Step 6: Scrambling,
Step 8: Adding a Weapon,
Finally: The Show,
322
324
325
Afterword
329
The Future of Robot Combat,
A
317
319
321
Step 7: Building the Frame,
15
330
Prototyping Electronics
335
Breadboarding and Using Prototyping Boards for Electronic Circuits,
Wire-Wrapping Prototyping,
Soldering for Robots,
337
337
Soldering Printed Circuit Boards,
Soldering Wires,
339
Soldering Connectors,
Crimp-Style Connectors,
Static Sensitivity,
305
306
340
339
339
338
336
ix
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Build Your Own Combat Robot
B
Resources and References
Robot Competition Web Sites,
Electric Motor Sources,
Battery Suppliers,
344
346
Electronic Speed Controller Vendors,
Remote Control System Vendors,
Mechanical Systems Suppliers,
Electronics Suppliers,
347
350
350
Robotics Organizations,
351
Other Robotics Resources,
C
346
347
348
Microcontroller Suppliers,
Reference Books,
352
Helpful Formulas
355
Chain Drive Centerline Distances,
356
Timing Belt Centerline Distances,
357
V-Belts,
343
344
357
Index
358
Acknowledgments
We would like to thank Mike Greene of Robot Science and Technology magazine
for putting the team together to write this book. Bob Gross, Andrew Lindsey,
Ronni Katz, Carlo Bertocchini, and Steve Richards provided a lot of top-quality
support and information, as well. Without their help, the quality of this book
would not be where it is now. We would also like to thank Carlo Bertocchini and
Grant Imahara for taking time out of their busy schedules to serve as technical editors. They provided valuable comments and insights that vastly improved our
work. Mark Setrakian, Peter Abrahamson, Christian Carlberg, Peter Menzel,
Larry Barello, Dave Owens, Jamie Hyneman, Vincent Blood, Clare Miles, and
Ken Gracey were of great help in providing excellent photos. A special thanks goes
to Dave Johnson for his help in interviewing Christian Carlberg, Grant Imahara,
Jim Smentowski, Stephen Felk, Donald Hudson, and Jamie Hyneman for the
“First Person” stories you’ll find throughout the book. Additional thanks go out
to the people at Vantec, Hawker, IFI Robotics, Parallax, Panasonic, National
Power Chair, Acroname, Futaba, and Grainger for their technical support and use
of some of their photos. Finally, we would like to thank Margie McAneny, Lisa
Wolters-Broder, Michael Mueller, and the whole team “behind the scenes” at
McGraw-Hill/Osborne for their patience and help in putting this book together.
Pete adds: I would like to thank my wife, Kristina Lobb Miles, for all of her tireless
help. With her brilliant skills in graphics manipulation, she was able to put together
most of the artwork and photos. Without her help, this project would not have
happened. She is a wonderful person and deserves a lot of credit. Tom Carroll,
too, deserves a lot of credit for putting this together. His infinite knowledge of robotics and ability to write lots of information in a very short time period is greatly
appreciated.
Tom adds: I would like to thank my wife, Sue, for her tireless support and
encouragement of my many robotics activities for the past 35 years. She has endured my many trips to all over that took me away from home and my family,
watched as various robots grew to completion in my shop, patiently waited as I
spent many hours in my office typing away at this book, and listened politely as
I talked for hours on end about robots. I would also like to thank Pete Miles for his
patience, organization, great knowledge, and tremendous effort at spearheading
this project. His wife Kris proved to be a most valuable asset at making the graphics
and manuscript flow to perfection. These two are a most incredible team, and without them, this book would have been only a pile of papers scattered on the floor.
xi
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Introduction
Some kids spend their free time playing sports. I spend mine building robots. You
may think that this is not a typical hobby for a teenaged girl, and you’re right. I am
part of a rapidly-growing community of combat robot builders from all across the
U.S., of all ages, and I’m not exactly new to the sport, either. I was at Fort Mason
San Francisco in 1994 watching the first robotic combat competition, Robot
Wars. I saw my dad win match after match with his flimsy, garage-built aluminum
contraption, and beyond all reason of my then seven-year-old brain, I was inspired. The next year, when I was eight, I had a flimsy, garage-built aluminum
contraption of my own, and I was ready to roll. Since then I’ve been hooked.
Through my few years of experience in the field of robotic combat, I’ve come to
realize that the actual battles—the end result of all my hard work—are not the
only things that I have to look forward to. Just as important to me are the people
and friends involved, the familiar sounds and smells of machine maintenance, the
ebb and flow of people excitedly preparing for competition, the long but rewarding hours of taking robots apart and putting them back together again, and the
feeling you get when you realize you’ve become a small but integral part of our
quirky little robo-community.
I hope this book will help you get started in the unique and exiting sport of robot
combat. Robot experts clearly explain everything you need to know to build a bot of
your own. For anyone thinking of building a robot, I strongly encourage you to give
it a try. You may not wind up with the super-heavyweight champ after your first
fight, but I guarantee it will be an experience you’ll never forget!
Cassidy Wright,
builder of Triple Redundancy, Fuzzy Yum Yum, and Chiabot
Orinda, California
January 2002
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xiii
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About the Authors
A
bout the Authors...
Pete Miles has been experimenting with robots since the mid 1970s. He used to
scavenge every part he could from dumpsters at radio and TV repair shops, and he
still uses parts that he collected back then in his current robot projects. After serving in the U.S. Marine Corps as a tank killer, he obtained bachelor’s and master’s
degrees in mechanical engineering. He currently works as a senior research engineer,
developing advanced machining technologies using 55,000 psi abrasive waterjets
for Ormond LLC, in Kent, Washington. As he puts it, “There is not a material in
the world a waterjet can not cut, including diamonds.” Miles is currently an active
member of the Seattle Robotics Society, the world’s largest robotics club, and was
recently appointed to the SRS Board of Directors. He is an avid competitor in autonomous robot sumo, and enjoys building legged robots for various contests to
demonstrate that walking robots can be formidable competitors.
Tom Carroll has been involved with robotics for more than 40 years. He built his
first robot at age 14, and later worked as a robotics engineer on NASA projects with
Rockwell International for nearly 30 years. Carroll co-founded the Robotics Society of Southern California in 1978 and is now active in the Seattle Robotics Society.
He designed robots for the International Space Station, to explore the surface of
other planets and to assist astronauts in space. He founded Universal Robot Systems to design and build robots for such feature films as Revenge of the Nerds and
Buck Rodgers in the 25th Century. He is presently a novel and technical writer,
and spends much of his time developing a truly functional personal robot to assist
the “forgotten generation,” the elderly, and give them pride in independent living.
Carroll moved from Long Beach, California, several years ago and now lives in the
Pacific Northwest, on Orcas Island off Washington’s coast. Tom enjoys kayaking,
hiking, and traveling with his wife.
A
bout the Contributors...
Bob Gross became involved with robotics in 1978 by building a working facsimile
of R2D2. For fun, he has built winning autonomous robots for sumo, maze, navigation, wandering, and combat. Later, he produced three autonomous museum
robots that would fetch balls, go to various colored columns, or allow
teleoperated control. By day, Gross works as a rocket scientist and has a small
company that focuses on various aspects of robotics, including machine vision.
Dave Johnson is a technology writer and scuba divemaster. The author of
18 books, Johnson covers popular technology like mobile gadgets, photography,
digital music, and robotics. He’s also an award-winning wildlife photographer and the author of The Wild Cookie, an interactive kids’ story on CD-ROM.
xv
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Build Your Own Combat Robot
Ronni Katz is an adjunct professor of computer science at DeVry College of Technology in North Brunswick, New Jersey. She was an original member of “Team
Spike” at the first Robot Wars competition and has helped design and build combat
robots that have won and placed highly at numerous competitions. Katz is a
proud member of the Society Of Robotic Combat and produced the 1998 nonprofit instructional video Introduction to Robotic Combat, which helped many
beginners get their start in the world of sport robotics. Katz writes fiction under
the pen name of Ron Karren and has been published in numerous fanzines. Her
first military technothriller novel, Wing Commander, can be found at bookstores
nationwide. You can visit Katz online at QuestPress.com for news of her future
publications.
Andrew Lindsey has been competing in robotic combat since 1996. In addition
to competing in all three major televised robotics competitions, he was one of four
combat judges at the November 2000 BattleBots event. Lindsey lives in New Jersey and designs fiberoptic interface electronics for a living. He competes regularly
in the North East Robo-Conflict events in the New Jersey/Pennsylvania area.
Steve Richards has been fascinated by the prospect of fully-autonomous robotics
since his childhood. He founded and runs the robotics company Acroname, Inc. in
an effort to advance robotics through information, parts, and a robotics community.
When he isn’t milling, coding, wiring, or ranting about robotics, he also enjoys
running. He lives in Boulder, Colorado, with his wife, Karen. Richards admits
that the only truly successful autonomous creation he has been involved with is his
daughter, Annie.
Cassidy Wright has been involved with robotic combat since 1994. She built her
first bot when she was just eight years old. She is a teenager now, and the builder of
Triple Redundancy, Fuzzy Yum Yum, and Chiabot.
A
bout the Technical Editors...
Carlo Bertocchini has been building competitive robots since 1993, and he worked
as a mechanical engineer until 2001. Now he divides his time between competing
in BattleBots matches and running his company, RobotBooks.com. He is the designer and builder of Biohazard, the world’s most successful combat robot. You can
learn more about his robots at www.robotbooks.com/biohazard.htm. Bertocchini
lives in Belmont, California, with his wife, Carol.
Grant Imahara is an animatronics engineer and modelmaker for George
Lucas’ Industrial Light & Magic in Marin County, California. He specializes in
electronics and radio control at the ILM Model Shop and has installed electronics
in R2D2 units for Star Wars: Episodes 1 and 2, and the famous Energizer Bunny.
For fun, Grant competes in BattleBots with his robot Deadblow, which set a record for the most number of hits in the first season of the show. Grant lives in a
loft in Oakland, California, where he also works on his robot in his spare time.
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chapter
1
Welcome to
Competition Robots
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