Dynamics modeling and controller design for a self-balancing unicycle robot

A self-balancing unicycle robot, which consists of a wheel for balancing and movement in longitudinal (pitch) as well as a flywheel for balancing in lateral (roll), is studied in this paper. The Lagrange approach is used to formulate the dynamic model, and the control algorithm of the self-balancing unicycle robot is presented. Because of the structure feature, there is no direct force to change yaw direction of the unicycle robot, only can we achieve it by using the interaction between individual motions in the yaw, pitch and roll direction. Simulation results validates that the unicycle robot can both change the yaw direction and keep its posture stable.