Hysteresis Modeling Method Based On Modified J–A Model In Smart Material Actuators

Smart material actuators, with high force, large strain, and nanometer solution, enjoy wide range of employment in vibration control, robotics, micro-positioning, etc., nevertheless, the smart material actuators exhibit dynamic hysteresis. Such hysteresis seriously confines the actuator’s performances, e.g., oscillation, undesirable positioning error, or even instability in severe cases. Thus, for analyzing, controlling and using the actuators efficiently and effectively, an accurate actuator hysteresis model must be established.Attributed to material deformations i.e. magnetostriction, that takes place when the material is treated under an external magnetic field, magnetostrictive actuators are being investigated progressively for several micro-/nano-positioning, ultrasonic, robotics and vibration control applications, due to their high force capacity, high energy densities. The operating principle of these actuators is based on magnetostriction, which is a highly complex phenomenon because of the interactions of mechanical, magnetic, and electrical phenomena. This complexity is further combined with the non-linear performance of the material(generally Galfenol or Terfenol-D), in particular, the behavior of Terfenol-D, noticed at high frequencies and high drive levels. Several models are present in the current literature describing magnetostriction.The effective employment of magnetostrictive actuators technology in control applications, defined by high dynamics, demands a precise understanding of the dynamics of these actuators with an accurate mathematical model to carry out control strategies. However, this is usually hindered by nonlinearities of the actuator system as well as complexity of the model. Keeping in view this issue, this research has been established on the Jiles–Atherton mean field model for ferromagnetic hysteresis, extended to use in the magnetostrictive actuators. The theoretical model is discussed with its extension to the actuator and the results are obtained.This work presents hysteresis modeling in the context of control applications for magnetostrictive actuators that demand an exact depiction of the input current – output strain relationship. Attributed to the inherent properties of magnetostrictive materials, this relation characteristically displays significant nonlinearities and hysteresis in the output. The characterization taken into account in this work has its basis on the J–A model in conjunction with a magnetostriction model of quadratic moment rotation. The hysteresis model presented here quantifies hysteresis loops very effectively. Then it can be used also to characterize accurately the strain output of the actuator at moderate drive levels. The model offers a benefit of flexibility under varying operating conditions.