Modeling and control of a pedaled, self-balanced unicycle

In this paper, a pedaled, self-balanced, personal mobility vehicle is developed. The vehicle is structurally similar to a pedaled unicycle but uses a brushless DC (BLDC) hub motor as its main driving wheel. Two control issues are investigated. Firstly, the vehicle is open-loop unstable, so one needs to regulate the motor torque properly regulated to stabilize the vehicle for easy maneuvering purposes. Secondly, to achieve smoothness and efficiency, upon receiving the torque command, the motor should be switched to an appropriate mode to accurately generate the torque demanded. To address these issues, controllers of two levels are proposed.