Study on the Stability and Motion Control of a Unicycle (3rd Report, Characteristics of Unicycle Robot)

摘要

In this paper, the characteristics of a unicycle robot are determined by analyzing a unicycle robot with an asymmetric rotor and closed-link mechanisms. Firstly, the dynamic equations of motion are derived and the robot's postural stability control is analyzed. Then the results are compared with those obtained by experiment. Analytical results for closed-link mechanisms are also obtained and compared with experimental results. It is shown by the analysis that the system's controllability with an asymmetric rotor is better than that with a symmetric rotor, and the robot's postural stability control can be realized using only PD and D controllers when the system has an asymmetric rotor. Longitudinal stability is easily achieved because the closed-link mechanisms can improve the longitudinal stability of the system. Analytical results indicate that the longitudinal stability and lateral stability influence each other and the system is quite nonlinear. It is also found that our improved model simulates a human riding a unicycle more closely than the previous model in terms of control behavior.