Feedforward hysteresis calibration of piezoelectric actuator in AFM based on inverse model identification

Abstract

Atomic force microscopy (AFM) has been widely applied in the field of science and technology because it can observe and manipulate at the nanometer scale. The piezoelectric is a regular choice for the actuator of AFM because of its high resolution and fast response. However, the intrinsic hysteresis nonlinearity weakens the accuracy of the observation and manipulation of AFM. Aiming at the hysteresis problem of the piezoelectric actuators in AFM, a modified feedforward calibration method based on the Prandtl-Ishlinskii (PI) model was proposed. By the means of identify the parameters of inverse model directly, the modified method simplify the obtaining procedure for the PI inverse model. The restriction to obtain the inverse model was removed, and the computational complexity was decreased. Experiments validate that the method is effective in reducing errors due to hysteresis, and improving AFM image quality.