Nonlinear hammerstein model identification of amplified piezoelectric actuators (APAs): Experimental considerations

Actuators based on piezoelectric material have attracted much attention owing to their compact construction, large force generation, high precision, wide operating frequency range, fast response, and low power consumption. Their domain of applications is wide and keeps expanding. One of the mostly widely used types of these actuators is the amplified piezoelectric actuator (APA). APAs have been used in many control engineering applications such as vibration suppression and positioning. Their efficient use, however, requires a development of an accurate mathematical model. A number of nonlinear models were proposed in the literature. Among these models, Bounc-Wen (BW) model received a special interest due to its simplicity and its ability to model a wide range of hysterics behavior. This paper addresses some practical considerations that need to be addressed when using BW model to describe the dynamic behavior of APA. These issues include the selection of sampling frequency, the type of inputs used in parameter identification, and the parameter identification algorithms.