Page 240 - Robot Builder's Bonanza

Chapter 20

Moving Your Robot

By definition, all mobile robots move. To propel themselves across the floor, a robot might use
wheels, or perhaps tracks, maybe even legs. Moving your robot is called locomotion, and
how these wheels, tracks, and legs are arranged is called the drive geometry. There are many
variations of drive geometries, some relatively easy to achieve, and others not.
Selecting the right locomotion system and drive geometry involves figuring out what you
want your robot to do. But it also takes assessing the mechanical requirements of constructing
the drive mechanism. It’s easy to “bite off more than you can chew,” and design a robot pro-
pulsion system that is not practical for you to build. A good example is robots with legs. These
are much harder to build than wheeled bots, and they often require regular maintenance to
keep everything tight and aligned.
In this chapter you’ll learn about locomotion systems and drive geometries, and how to
select the best one for the robot you’re building.

Chapters 26 and 27 in Part 4 contain additional specific details about using locomotion
G principles to power three common types of robots: wheeled, tracked, and legged. This chapter
introduces you to the basic concepts, plus issues common to all three varieties of locomotion
systems.

Choosing a Locomotion System

Let us take a quick look at the three main locomotion systems used with mobile robots. Don’t
worry if some of the terminology in the comparison table is new to you; I’ll explain it to you
as we go along.

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