Pitch and Roll Control of an Active Omni-Wheeled Unicycle using LQR and Sliding Mode Controller

A unicycle with only one supporting contact point on the ground is unstable in both the pitch and roll directions. This paper presents a novel active omni-wheeled unicycle as a new self balancing unicycle system. The decoupled dynamics of the roll and pitch axes are derived using the cart and wheel inverted pendulum model. LQR and sliding mode controllers are applied for full state control using the Euler Lagrange dynamics modelling method. Results are conducted by simulation and experiments to evaluate the control performance of the controller on each axis.