Modeling and compensation control of asymmetric hysteresis of piezoceramic actuator

ZHAO Xiao-xing， JIANG Wei， LI Wei
（State Key Laboratory of Digital Manufacturing Equipment and Technology，Huazhong University of Science and Technology，Wuhan 430074，China）

Abstract： Aiming at the disadvantage of the conventional Bouc-Wen model in formulating the asymmetric hysteresis of piezoceramic actuators，a modified Bouc-Wen model was proposed so as to improve the accuracy of model-based compensation control of piezoceramic actuators. The modified Bouc-Wen model was introduced by ameliorating shape control parameters to simulate the asymmetric hysteresis curve of piezoceramic actuator. The parameters of the modified Bouc-Wen model were identified by particle swarm optimization algorithm. Feedforward compensation control as well as feedforward plus PI feedback control based on the proposed model were carried out to investigate its effectiveness on improving the displacement output accuracy. In comparison with control experiments by using the traditional Bouc-Wen model，the displacement output error by using the modified Bouc-Wen model could be reduced by approximately 42% in open-loop feedforward control and 20% in feedforward plus PI feedback control. The results indicate that，for the same control method，compensation control by using the modified Bouc-Wen model can achieve higher trajectory tracking accuracy. Furthermore，model-based feedforward plus PI feedback can achieve better control accuracy in comparing with only feedforward control.
Key words： piezoceramic actuator； Bouc-Wen model； asymmetric hysteresis； hysteresis model； parameter identification； compensation control