By definition, all mobile robots move from place to place. They need to be able to move forward, to reverse, and to turn to the left or right. Robots are often operated in confined spaces so it useful to be able to spin on one spot. Variable speed is less important and often unnecessary.
The Quester (Project 4, p. 258) runs on three wheels. Two of these, to the left and right, are the drive wheels. Each has its own electric motor. The third wheel is a castor, used for balance.
The panel on the right tells you where to look for details.
The Scooter (p. 165) also has three wheels, but uses only one motor. Its steering is somewhat erratic but very easy and cheap to build!
Was this article helpful?