Precise positioning of piezo-actuated stages using hysteresis-observer based control

The piezo-actuated stages are composed of the piezoelectric actuator and the positioning, mechanism. The positioning accuracy of the piezo-actuated stage is limited due to hysteretic nonlinearity of the PEA and friction behaviour of the positioning mechanism. To compensate this nonlinearity of piezoelectric actuator, a PI feedback control associated with feedforward. compensating based on the hysteresis observer is proposed in this paper. To verify the consistency of the proposed method, the experiments are implemented by real-time control to be compared with the numerical simulation. (C) 2006 Elsevier Ltd. All rights reserved.