Advanced adaptive control for piezo-actuated nano-positioner

The piezo-actuated nano-positioner is composed of a piezo electric actuator (PEA) and a positioning mechanism (PM). Due to the hysteretic nonlinearity in the PEA and the friction in the PM, the high precision control of the piezo-actuated nano-positioner is a very challenging task. In this paper, a new adaptive control law for the positioner is proposed, where the parameterized hysteresis model is employed. The proposed control law ensures the global stability of the controlled stage, and the position error can be controlled to approach to zero asymptotically. The advantage is that the real values of the parameters of the positioner need to be neither identified nor measured, and very high precision tracking can be achieved. Experimental results show the effectiveness of the proposed method.