State Estimation of Micropositioning Stage With Piezoactuators

In this paper, a nonsmooth Kalman filtering method is proposed for noise suppression of micropositioning stages with piezoelectric actuators described by the so-called sandwich model with hysteresis. According to the characteristics of the system, a nonsmooth stochastic state-space equation is constructed. In this model, an autoswitcher is introduced to adapt the nonsmooth operation conditions. Then, the convergence of the novel Kalman filter is discussed. Subsequently, the comparison in simulation between the proposed filtering scheme with the unscented Kalman filter and particle filter is presented. Finally, the experimental results on a micropositioning stage with piezoelectric actuator are illustrated.