PID saturation function sliding mode control for piezoelectric actuators

A wide variety of feedback control schemes have been successfully applied to the piezoelectric actuators (PEAs). Among them, it is known that sliding mode control (SMC) is superior to matched uncertainties but suffers the problems of chattering and “integrator windup” when introducing integral term in the controller. In allusion to the problems mentioned above, this paper presents a novel sliding mode controller (SMC), which uses proportional-integral-derivative (PID) replacing the saturation function. Then, the proposed feedback control scheme is combined with a feedforward controller, which comprises an approximated ZPETC and the inverse of the modified Prandtl-Ishlinskii hysteresis model. Finally, the proposed control method is implemented in a real piezoelectric actuator device. Experimental results show that the proposed control scheme has a better transient performance than the PID-based sliding mode control (PIDSMC) meanwhile preserves tracking accuracy.