Winning Design! (eBook)

James J. Trobaugh is an experienced coach and leader in the FIRST LEGO League. He is author of the acclaimed book Winning Design!, focusing on the physical aspects of LEGO MINDSTORMS robot design. He has been involved with the FIRST LEGO League since 2004 as coach for Team Super Awesome, and as a technical judge at the LEGO World Festival. He is also the FIRST LEGO League Director of the Forsyth Alliance in Forsyth County, Georgia. James started out as a LEGO hobbyist by founding the North Georgia LEGO Train Club in 1998, and has found in LEGO robotics a natural blending of his LEGO hobby and his day job as a software architect. An added bonus is the joy of sharing his love of technology not only with his own children, but with kids in general.James J. Trobaugh has a degree in Computer Science and has been working as a software architect for 26 years. He lives in the Atlanta, Georgia area with his two children, Ian and Amy.James has been involved with FIRST LEGO League since 2004 as a coach for TeamSuper Awesome and as a technical judge at the LEGO World Festival. He was also the FLL director of the Forsyth Alliance in Forsyth County Georgia.James started out as a LEGO hobbyist by founding the North Georgia LEGO Train Club in 1998 and has found that LEGO robotics is a natural blending of his LEGO hobby and his day job as a software architect. The added bonus is the joy of getting to share his love of technology not only with his own children but with kids in general.

Contents at a Glance 5
Contents 6
About the Author 13
About the Technical Reviewer 14
Introduction 15
Chapter 1: Design Considerations 17
Understanding the Rules 17
Knowing the FIRST LEGO League Robot Parts Rules 18
Studying the Game Mission Rules 18
Grouping Missions into Zones 19
Tasking the Missions 19
Mapping Out the Field 20
Working with Constraints and Obstacles 21
Field Obstacles 22
Environmental Conditions 23
The EV3 Software 24
Understanding the LEGO MINDSTORMS Hardware 25
EV3 Intelligent Brick 25
Touch Sensor 27
Gyro Sensor 27
Color Sensor 28
Ultrasonic Sensor 28
Large Servo Motor 29
Medium Servo Motor 29
Beginning the Design Process 30
Brainstorming as a Team 30
Presenting Your Design 31
Drawing Your Design 31
Resource Contention 32
Summary 32
Chapter 2: Chassis Design 33
Understanding Basic Design Aspects 33
Size 33
Power 34
Speed 34
Batteries 34
Finding the Center of Gravity 34
Gearing Up 38
Spur Gears 38
Crown Gears 39
Bevel Gears 39
Double Bevel Gears 40
Worm Gears 41
Clutch Gears 41
Pulleys 42
Knob Wheel 43
Gear Ratios 43
Getting Your Wheels 45
Circumference 45
Mounting 46
Treads 48
Exploring the Most Common Chassis 49
Two-Wheeled Robots 49
Three-Wheeled Robots 50
Four-Wheeled Robots 50
Tracked Robots 51
Troubleshooting 52
Summary 53
Chapter 3: Going Straight 54
Design Influences 54
Wheelbase 54
Weight 55
Wheel Circumference 55
Wheel Support 56
Programming to Go Straight 58
Move Steering Block 59
Move Tank Block 59
Custom MyMove Steering Block 60
Batteries 65
Replaceable Batteries 65
Rechargeable Battery Packs 66
Helpers 66
Wall Following 66
Base Jigs 70
Tips 70
Motor Matching 70
Removing Gear Slack 71
Troubleshooting 72
Summary 72
Chapter 4: Consistent Turning 73
Turning Designs 73
Differential Steering Systems 73
Steering Drive Systems 75
Calculating Turns 76
Single-Wheel Turns 76
Dual-Wheel Pivot 78
Programming 79
Move Steering Block 79
Move Tank Block 80
Creating a Custom MyPivot Block 80
Creating a Custom MyTurn Block 82
Gyro Sensor 82
Calibrating the Gyro Sensor 83
Using the Gyro Sensor to Make a Turn 83
Mounting the Gyro Sensor on Your Robot 84
Summary 84
Chapter 5: Line Following and Detection 85
EV3 Color Sensor 85
Ambient Light 86
Reflective Light 86
Color Mode 86
Positioning the Color Sensor 86
Calibrating the Color Sensor 88
Making the Calibration 88
Using the EV3 Calibration Block 88
Using a Local File 90
Viewing the Calibration 91
Deleting Calibration Data 92
Shielding the Color Sensor 92
Line Following 93
A Dual-State Example 93
Defining More Than Two States 94
Implementing a Proportional Algorithm 96
Using Dual Color Sensors 97
Line Detection 98
Finding a Line 99
Detecting Color in Lines 101
Summary 101
Chapter 6: Squaring Up 102
Squaring Up 102
Squaring Up with Walls 102
Passive Wall Squaring 103
Interactive Wall Squaring 106
Aligning with Lines and Edges 108
Summary 109
Chapter 7: Collision Detection 110
Touch Sensor 110
Monitoring the Pressed State 110
Detecting the Released State 113
Achieving the Bumped State 114
Color Sensor 115
Ultrasonic Sensor 117
Summary 118
Chapter 8: Passive Attachments 119
Types of Passive Attachments 120
Pushing 120
Bumper 120
Plow 121
Delivery Box 122
Hooking 123
Simple Hook 123
Fishing Hook 125
Carabiners 125
Fork 127
Dumping 128
Collecting 131
One-Way Box 131
Sweeper 133
Spring-Loaded Attachments 133
Attachment Interfaces 135
Snapping Pins 136
Nonsnapping Pins 136
Magnets 137
Summary 138
Chapter 9: Power Attachments 139
Power Attachment Locations 139
Adding an Attachment to the Front 139
Adding an Attachment to the Center 140
Adding an Attachment to the Rear 141
Types of Attachments 142
Attachments That Grab 142
Claw 142
Vise Grip 143
Trap 143
Attachments That Lift 145
Lever 145
Forklift 146
Attachments That Push 146
The LEGO Actuator 147
Custom Actuator 148
Power Interfaces 149
Direct Connections 149
Gears 150
Driveshaft 151
Summary 152
Chapter 10: Pneumatics 153
Operation of Pneumatic Parts 153
Available Pneumatic Parts 154
Pumps 155
Air Tank 156
Pneumatic Switches 157
Pneumatic Actuators 158
T-Joints and Air Hoses 159
Air Gauges 160
Integrating Pneumatics with the EV3 Robot 161
Starting Out 161
Triggering the Attachment 162
Building Attachments 162
Summary 163
Chapter 11: Master Programs 164
My Blocks 164
Defined Start and End Events 164
Example Mission Code 165
Simple Sequencer Program 166
The Setup 166
Creating My Blocks 167
Creating the Sequencer 167
Looking at the Code 167
Creating a Better Sequencer 168
Program Navigation 168
Sequence Rollover 169
Creating an Advanced Sequencer 173
Program Display 174
Saving State 175
Summary 176
Chapter 12: Program Management 177
Ev3 Updates 177
Managing Source Code 180
Single Computer 181
Network of Shared Computers 182
Flash Drives 182
File Naming 182
Summary 183
Chapter 13: Documentation and Presentation 184
Program Documentation 184
Program Description 184
Printed Copies of Programs 186
Robot Design Documentation 187
Documenting Chassis Design 187
Attachment Design and Description 188
Presenting to the Technical Judges 189
Describing Your Solution Process 189
Presenting Your Technical Notebook 189
Talking to the Judges 190
Summary 190
Appendix A: Building DemoBot 191
Index 268