Dynamic modeling and identification of magnetostrictive actuators for control of micromanipulation

Magnetostrictive actuators featuring high energy densities, large strokes and fast responses appear poised to play an increasingly important role in fields of requiring micro positioning. However, such actuators invariably exhibit dynamic and hysteretic behaviors that could cause oscillations and error in the micro positioning tasks. Therefore, it is extremely important to develop a dynamic model to describe such dynamic behaviors. Until now, there is no comprehensive model in the literature that can characterize dynamic behaviors of the actuators, including frequency responses, current-magnetic flux hysteresis, nonlinear magnetic behavior, and loading effects. This paper aims to develop such a comprehensive model. The developed model is based on the principle of operation of the magnetostrictive actuator, which comprehensively considers the electric, magnetic and mechanical domain as well as the interactions among them. To validate the developed model, the parameters of the model are identified when the hysteresis effect of the magnetostrictive actuator is represented, as an illustration, by the Prandtl-Ishlinskii (PI) model. Experimental validation is conducted on a magnetostrictive actuated platform. The experimental results illustrate that the comprehensive model has a excellent agreement with the dynamic behavior of the magnetostrictive actuator.