Research On Nonlinear Hysteresis Model Of Piezoceramics

With the development of science and technology, micro/nano precision positioningsystem has become hot spots, and driving device performance has a great influence on thepositioning accuracy. Piezoelectric ceramic actuator is widely used in micro positioningsystem with the advantages of small size, large capacity, high resolution, no noise and nofever. But it also has the phenomenon of hysteresis nonlinearity, which hinders theimprovement of system positioning accuracy.For this problem, this paper puts forward a method to reduce hysteresis nonlinearityby setting up hysteresis model and carrying on effective control, combined with thenational natural science fund project--"Research on piezoelectric ceramic drivingmechanism and control method in high speed dynamic precision positioning situation ".First, PI hysteresis model of piezoelectric ceramic is established based on Prandtl-Ishlinskii hysteresis operator, and the established hysteretic model can accurately describethe hysteresis nonlinearity phenomena of Piezoelectric ceramics. The initial load functionis used to analyse and deduce the PI hysteresis model on the basis of previous work, and PIhysteresis inverse model of piezoelectric ceramic are obtained as a result. This provides amodel basis for the adaptive inverse control of piezoelectric ceramic actuators.Based on the established PI hysteresis model and its inverse model of piezoelectricceramic, the adaptive inverse control algorithm is designed by applying LMS filter, and itcan effectively realize the adaptive adjustment of PI hysteresis model weight coefficient ofpiezoelectric ceramics. Micro positioning experiment system is established and theestablished PI hysteresis model has carried on the experimental study. The experimentalresults show that, the system output linear error can be reduced from17.7%to1.43%bythe use of adaptive inverse control algorithm.According to the characteristics of the piezoelectric hysteresis curve and microscopicpolarization theory foundation, linear transformation hysteresis model is established.Through the analysis of Wiping-out of piezoelectric hysteresis curve, improved linear transformation hysteresis model is established. The accuracy of the established model isverified through the comparison of the measured values and the hysteresis curve predictedby model.