A Design of a Control Method for Changing Yaw Direction of an Underacuatted Unicycle Robot

We have developed a unicycle robot that consists of a body, a disk driven by a dc motor for rotation, and a wheel driven by another dc motor to move the body. Since there is no direct force for changing the yaw direction of the robot, conventional controllers cannot change the yaw direction. The present paper proposes a control method for changing the yaw direction by using the interaction between individual motions in the yaw, pitch, and roll directions. Simulation results show the performances of the proposed controller. 1) The proposed control method is useful for a regulator problem and can control the yaw direction of the unicycle robot toward zero from any initial value. 2) The controller can cancel a disturbance applied to the robot motion.