High precision adaptive control for piezo-actuated stage

The piezo-actuated stage is composed of a piezo electric actuator (PEA) and a positioning mechanism (PM). Due to the existence of hysteretic non-linearity in the PEA and the friction in the PM, the high precision control of the piezo-actuated stage is a challenging task. This paper discusses the high precision adaptive control for the piezo-actuated stage, where the hysteresis is described by Prandtl-Ishlinskii model. Only the parameters which are directly needed in the controller design are estimated. The proposed control law ensures the global stability of the controlled stage, and the position error can be controlled to approach to zero asymptotically. Experimental results show the effectiveness of the proposed method.