Hysteresis compensation and adaptive controller design for a piezoceramic actuator system in atomic force microscopy

This paper presents an indirect adaptive controller combined with hysteresis compensation to achieve high scanning performance of an atomic force microscopy (AFM) system. Dynamic model of a piezoceramic actuator system in AFM is derived and analyzed by using standard system identification method. The indirect adaptive controller is designed to achieve desired tracking performance as well as to deal with system parameters variation based on the identified model of the piezoceramic actuator system. A feedforward controller based on the Preisach model is proposed to compensate the nonlinear hysteresis effect. Experimental results indicate that the proposed controller can significantly improve the tracking control accuracy of the piezoceramic actuator as well as achieve high scanning performance of the AFM system. Maximum scanning error was reduced from 2 mum to 0.3 mum in comparison with proportional-integral-derivative (PID) controlled AFM.