Modeling and identification of piezoelectric hysteresis by an asymmetric Bouc-Wen model

The motion performance of piezoelectric actuator is restricted by its hysteresis nonlinearity in the application of precision positioning. A novel hysteresis modeling method based on Bouc-Wen model is proposed to describe the asymmetric hysteresis nonlinearity of piezoelectric actuator. Considering the fact that the classical Bouc-Wen model is only a symmetric model, the proposed model is developed for describing the asymmetric hysteresis characteristic of piezoelectric actuator. Different from the commonly used approach for developing asymmetric Bouc-Wen model by introducing parameters to modify the nonlinear component, the proposed model only modified the linear component by introducing a general input function. By this way, the proposed model not only has a relatively simple mathematical form, but also has fewer parameters to characterize the asymmetric hysteresis characteristic. Particle swarm optimization is used to identify the parameters of the proposed model, and different experiments are conducted on a piezoelectric actuator to validate the developed model. Experimental results demonstrate that the asymmetric hysteresis characteristic of hard piezoelectric material can be effectively described by the proposed model.