Inverse-feedforward of charge-controlled piezopositioners

Inverse-feedforward control can substantially improve the performance of piezoelectric positioners (piezopositioners). The feedforward-input is found by modeling and inverting the piezopositioner dynamics. The primary challenge in such an approach is the complexity of modeling and inverting the hysteresis nonlinearity in the piezopositioner dynamics. The main contribution of this work is to alleviate this complexity by using charge control to linearize the overall dynamics and then model and invert the simplified (linearized) dynamics. The proposed approach is applied to an experimental piezopositioner and results are presented to contrast the feedforward-based positioning performance with and without the use of charge control to linearize the dynamics. (c) 2007 Elsevier Ltd. All rights reserved.