Balancing control of a unicycle riding

Using gyroscopes to power human forwards and backwards only a single wheel is needed to make a ridable vehicle which will be much smaller and lighter. In order to retain dynamic and static stabilities of the vehicle, a self-balancing stabilized unicycle robot is proposed for human riding. The actuation and balancing mechanism consists of two separate actuators: the drive motor causes forward and backward acceleration, by driving the wheel directly through. The spin motor spins a suspended flywheel at a high rate, imparting dynamic stability to the robot in the lateral plane (only leaning to the left or right, no leaning to the front or back). In this paper, the unicycle robot system is simplified to the inverted pendulum subsystem and the inertial-wheel pendulum subsystem. Based on the modeling method of the under-actuated mechanical system, the dynamics in the longitudinal plane and the lateral plane are developed respectively. Then a LQG structure to balance the unicycle robot at the vertical position is designed by linearizing the dynamic equations. Finally, the feasibility of the models and the controllers are verified by using the simulation results.