High Precision Control for Piezo-Actuated Positioners

The piezo-actuated nano-positioner is composed of a piezo electric actuator (PEA) and a positioning mechanism (PM). Due to the existence of hysteretic nonlinearity in the PEA and the friction behavior in the PM, the accurate position control of the piezo-actuated stage is a challenging task. This paper discusses the adaptive sliding mode control for the piezo-actuated nano-positioner, where the hysteresis is described by Prandtl-Ishlinskii model. This paper tries to fuse the hysteresis model with the adaptive control techniques, where the real value of the parameters of the stage need neither to be identified nor to be measured. The proposed control law ensures the global stability of the controlled nano-positioner, and the position error can be controlled to be as small as required by choosing the design parameters. Experimental results show the effectiveness of the proposed method.