Abstract: A compounding control method with feedforward compensation and feedback control is presented in order to balance the accuracy and stability, improve the performance of piezoelectric ceramic actuator, and then to get high positioning accuracy for micro-motion worktable drived by piezoelectric ceramic actuator. Feedforward compensation is feedforward control based hysteresis model of piezoelectric ceramic actuator and is realized through self-learning algorithm, the aim of which is to compensate piezoelectric hysteresis and improve tracking ability to reference displacement signal. Feedback control is PID control, which eliminates the residual error of feedforward compensation and the error caused by uncertainty of model. Moreover, traditional PID control is improved to be variable-coefficient integrals and weighted differential PID to decrease the integral saturation and differential sensitivity to disturbance. This compounding control method is validated by experiments and compared with other control strategies, such as open loop control, feedforward control and PID control. The results demonstrate that the motion worktable under compound control has better performance than other control strategies.

Key words: Compounding control, Feedforward control PID control, Micro-motion worktables, Piezoelectric ceramic actuator