Robotics Instruction Course

Copyright 2003 by Beach Cities Robotics Team 294, all rights reserved.

Dale Hall, Bob Hosken, and Rick Wagner

Version 1.27, October 14, 2003, first created June 6, 2003

This document is written to accompany a course of instruction in robotics fundamentals for high school students participating in a competitive robotics team. Our intent in preparing the course content is to keep the material accessible to motivated high school freshmen yet allow it to be stimulating to seniors. The course covers topics essential to an understanding of robotics for a contributing competitive team member.

Robotics is a discipline at the intersection of mechanics, electronics, and computer science. As an area of research, the hard problems of robotics are algorithmic, so robotics is properly placed in the computer science departments of most universities. Robotic algorithms are founded on the physical world in which robots find themselves, so the mechanical and electrical topics are treated here first.

Part 1 is an introduction to mechanics that reviews analytic geometry and vectors before describing Newtonian statics. Part 2 is an introduction to strength of materials and structures. Part 3 is an introduction to mechanical design. Part 4 introduces electricity and DC circuits. Part 5 is an overview of motive power including batteries, motors, and control circuits. Part 6 is an introduction to computer programming. Part 7 introduces robot algorithms.

This document is maintained in Microsoft Word and exported to HTML format for Web publication. As such, it may be best viewed with Microsoft’s Internet Explorer. We have found that some versions of Netscape do not properly display the Greek letters used in some of the equations here.

FIRST team 294, Beach Cities Robotics, has many talented and highly productive female contributors. The English language has no gender-neutral singular personal pronoun. The use of the default masculine pronouns here for generic indication is not intended as a slight to the female gender. That’s just the way English grammar is, and professional technical writers often believe that grammatical correctness is more important than political correctness.

This instruction course material continues to be a work in progress and is updated from time to time (see the version history section). New sections under consideration include programming for the FIRST controller (Mark Miller) and teamwork and strategy (author TBD).


 

Table of Contents

1 Introduction to Mechanics. 8

1.1 Review of Cartesian Geometry. 8

1.1.1 Points in the Plane. 8

1.1.2 Points in Space. 9

1.1.3 Lines. 9

1.1.4 Surfaces. 10

1.1.5 Volumes. 10

1.2 Vectors and Forces in the Plane and in 3D.. 11

1.2.1 Forces and their Representations. 11

1.2.2 Point Forces. 11

1.2.3 Magnitude and Direction. 12

1.2.4 Components of Forces. 12

1.2.5 Vectors: Direction, Velocity, Force. 12

1.2.6 2D Force Vectors. 12

1.2.7 3D Force Vectors. 12

1.2.8 Newton’s Law of Transmissibility. 12

1.3 Resultant Forces and Moments. 12

1.3.1 Vector Operators: Sum, Difference, Scalar Multiplication. 12

1.3.2 Moments, Torques, Couples, and Wrenches. 13

1.3.3 Newton’s Laws of Motion: Linear and Rotational 13

1.4 Statics: Reactions and Free Body Analysis. 13

1.4.1 Newton: Action and Reaction. 14

1.4.2 Statics: Sum of Forces = 0 = Sum of Moments. 14

1.4.3 Solving Static Equations. 14

1.4.4 Static Equilibrium and Indeterminism.. 16

2 Strength and Structures. 17

2.1 Stress and Strain. 17

2.1.1 Tensile Stress and Strain. 17

2.1.2 Compression Stress and Strain. 17

2.1.3 Shear Stress and Strain. 18

2.1.4 Bulk Stress and Strain. 18

2.2 Tension-Compression, Bending, and Torsion. 18

2.2.1 Tensile (Compressive) Stress. 18

2.2.2 Bending Stress. 18

2.2.3 Torsional Stress. 20

2.3 Material Properties, Test, and Analysis. 21

2.3.1 Strength. 21

2.3.2 Stiffness. 21

2.3.3 Other Material Properties. 21

2.3.4 Materials Testing. 22

2.3.5 Analyzing Designs. 22

2.4 Structures: Beams, Columns, Frames, Struts. 22

2.4.1 Beams. 22

2.4.2 Columns. 23

2.4.3 Moment Bearing Joints. 23

2.4.4 Frame and Panel 23

2.4.5 Struts and Trusses. 23

2.5 Deflection Analysis. 23

2.5.1 Axial Deflection. 23

2.5.2 Beam Deflection. 24

2.5.3 Torsional Deflection. 24

3 Designing Structures and Mechanisms. 25

3.1 Fabrication of Parts. 25

3.2 Assemblies, Bolted Joints, Welding. 25

3.2.1 Threaded Fasteners. 25

3.3 Friction. 26

3.4 Mechanical Advantage: Levers and Linkages. 26

3.5 Rotary Mechanisms: Gears, Chains, Belts, and Pulleys. 27

4 Electricity. 28

4.1 Basic Terms. 28

4.1.1 Voltage: Force that causes Charge to move. 28

4.1.2 Battery: Device with constant voltage, E. 28

4.1.3 Charge: Property of quantity of ions or electrons. 28

4.1.4 Current: Speed of charge motion. 28

4.1.5 Resistor: Electrical device that slows flow of charge. 28

4.1.6 Power: Rate of electrical energy flow.. 28

4.2 Schematic Symbols. 29

4.3 Example Circuit 30

4.4 Ohm’s Law.. 30

4.5 Measurements. 31

4.5.1 Put the Leads in proper socket 31

4.5.2 Put the pointer on appropriate measurement scale. 31

4.5.3 Caution. 31

4.6 Examples. 33

4.7 Expanded Example.