Load-Dependent Prandtl-Ishlinskii Modelling and Parameter Identification for Giant Magnetostrictive Actuator

This study addresses the modeling challenges of load-dependent and asymmetric hysteresis characteristics in Giant Magnetostrictive Actuator (GMA) by proposing an enhanced Prandtl-Ishlinskii (PI) model with load-dependent modifications. The developed model improves upon the classical PI framework through the incorporation of an arctangent envelope function to better characterize asymmetric hysteresis loops. Systematic parameter identification was implemented to establish the load-dependent modified PI model. Experimental validation was conducted using a dSpace platform to acquire input current and output displacement data across a load range of 0.15kg to 1.05kg.Quantitative evaluation of model accuracy was conducted using both RMSE and MAE criteria.Results demonstrate that the modified model achieves superior fitting accuracy with consistently reduced errors. Crucially, the model effectively captures key load-induced hysteresis variations including loop narrowing and slope changes, thereby successfully characterizing both the asymmetric and load-dependent hysteresis properties of GMAs within the specified operational load range.