Discrete-Time Linear Quadratic Tracking Control for Piezoelectric ceramic actuators

To mitigate the effects of hysteresis nonlinearity in piezoelectric ceramic actuators and enhance the tracking accuracy of piezoelectric micro-positioning platforms, a Hammerstein model is developed to characterize the system. A hysteresis compensator is designed based on the Bouc-Wen model to improve the system’s linearity. To address incomplete hysteresis compensation and external disturbances, a discrete-time linear quadratic optimal tracking (DLQT) control strategy based on Kalman filtering is employed to enhance the tracking accuracy. A Kalman filter is used to estimate the system states. The DLQT controller comprises a feedforward term that enables the system output to track the reference signal and a feedback term that ensures closed-loop stability. The hardware-in-the-loop experiments without load and with load show that the proposed control strategy can effectively improve the tracking control accuracy and robustness of the piezoelectric micropositioning platform.