Modeling and Parameter Identification of Piezoelectric Actuator in Micropositioning Systems

Due to the development of technology, actuators possessing high precision performances are increasingly needed more than before. Because of their high precision, fast expansion, and independence from the magnetic field, piezoelectric actuators are superior in comparison to other actuators based on smart materials. However, hysteresis, creep, and vibrational dynamics are challenges faced while working with piezoelectric actuators. Among those characteristics, hysteresis, which is a nonlinear behavior, degrades precision, bandwidth, and accuracy. In this paper, a dynamical model for a piezoelectric actuator is obtained, and the parameters of the hysteresis, vibration, and creep models are calculated. The Levenberg-Marquardt algorithm is used for identification of the parameters of the Normalized Bouc-Wen, and the C-H model. The calculated models are tested and validated by applying a multi-sine wave as an input to the experimental setup. Also, a differential equation form for the C-H model is calculated which can be used to design a nonlinear controller. The obtained nonlinear hysteresis, linear creep, and linear vibration models can then be connected in series to provide a model to describe the main characteristics of a piezoelectric actuator.