A Precise Positioning Method for Piezoelectric Driver Based on the Adaptive PI Model
Due to its high positioning accuracy,the piezoelectric ceramic tube( PZT) is widely used in ultra-precision machining,micro and nano measurement and other fields. However,the inherent hysteresis of piezoelectric ceramics seriously affects their positioning ac-curacy. The influence of driving range on the hysteresis of piezoceramic is studied,and the experimental results show that hysteresis is significant with the increase of driving range. In the application of PZT,the driving range is one of the main setting parameters. A fitting method based on the adaptive Prandtle-Ishlinskii( PI) model is proposed. The segmented interval is set according to the slope trend of hysteresis curves obtained under different driving ranges. The quadratic programming algorithm is used to identify the weight parameters of the PI model. Then the hysteresis curves are fitted according to the segmented interval. The method greatly improves the fitting accu-racy. An inverse model based on adaptive PI model is designed as a feedforward controller to compensate for hysteresis of PZT. An ex-perimental platform based on Labview is built to verify the feasibility of the algorithm. Experimental results illustrate that the feedforward controller based on the adaptive PI inverse model improves the positioning accuracy of PZT to 1.8 nm.
piezo driverhysteresisadaptive PI modelfeedforward controller
万方数据
维普
