Hammerstein-based model of piezoceramic actuator and its identification

For the effect of hysteretic linearity of a piezoceramic actuator on nano-positioning system, a modeling method based on Hammerstein model was proposed. The Hammerstein-based model for the piezoceramic actuator was established and its frequency dependence was described. By using the Hammerstein model, the piezoceramic actuator was taken as a static hysteretic model couple with a dyamic second-order system, and the former was described by the Preisach model and the latter was identified by the genetic algorithm. The experimental results show that the frequency dependence of the Hammerstein-based model is improved after adding the second order system, correspondingly, the error is decreased greatly. In 800 Hz, the absolute average tracking error of the Hammerstein-based model is 0.339 2 μm, which is less than that of the Preisach model in 0.888 1 μm.