SHEN Xiao-feng，ZHANG Wei

（College of Electrical Engineering，Zhejiang University，Hangzhou 310027，China）

Abstract：Aiming at solving poor stability and poor anti-load-disturbance ability of the electric unicycle，the self-tuning fuzzy PD  controller for posture control was investigated. In this system，accelerometer and gyroscope are attitude sensors and permanent magnet brush DC motor is actuator. On basis of analyzing attitude changes during riding，the dynamic model of an electric unicycle was set up， the relationship between attitude information and the motor output torque was built up. Combining conventional PD and fuzzy logic control scheme，the self-tuning fuzzy PD controller was presented to accomplish posture control. The traditional PD control and selftuning

fuzzy PD control were compared on an electric unicycle built in the laboratory. The results indicate that the proposed controller is more flexible and capable than ones with fixed parameters when the unicycle is ridded in different situations.

Key words：electric unicycle；self-tuning fuzzy PD control；dynamic model