The chassis of our robot is a four wheeled design. The rear wheels are used for propulsion, while the front wheels are for steering.
This design was chosen over a differential drive system because it allows for greater speed. The propulsion motor is not used for steering at all, which allows it to devote its full power to speed, even while the robot is turning. The front wheels are controlled by a servomotor, allowing for quick and accurate changes of direction. The downside of this design is that it has a much larger turning radius. A differentially driven robot can make 180 degree turns on the spot, while our robot would require a substantial forward movement to accomplish the same maneuver. However, a differential robot must slow down or stop to make any change in direction, which is not necessary for our robot.
Our original Steering system consisted of the wheels scavenged from an model car connected directly to the servomotor. This was used in our midterm run. (see Movies tab) However this was not very effective for large changes of direction. This system was changed to a geared turning system, which allows for a greater maximum turn rate.
