Using odometry for differential wheeled robots

A differential wheeled robot is commonly used by a small mobile robot, especially, in robot competitions. The major advantage is its turning system doesn´t need a turn around radius. However, it is hard to precisely control the distance and orientation by powering the two separately driven wheels placed on either side of the robot body. This paper presents a simple mathematical model of odometry, and two comprehensive equations have been derived to control the distance and orientation required by a robot to move accurately. Due to the simplicity of arithmetic computations, it is relatively easy to be implemented in almost any computer language. To verify its reliability and efficiency, we participated in a national robot competition held in Taiwan, Nov. 2011. Finally, we won the championship.