Characterization of rate-dependent hysteresis of magnetostrictive actuators

A generalized Prandtl-Ishlinskii model is proposed for modeling the rate-dependent hysteresis behavior of magnetostrictive actuators. The shape of hysteresis loops in these actuators depends on the rate of change of the input current. A generalized rate-dependent play operator is formulated and integrated to the Prandtl-Ishlinskii model together with density function to model hysteresis as a function of rate of change of the input. A dynamic threshold function is further proposed to enhance the prediction of rate-dependent asymmetric hysteresis effect in magnetostrictive actuators. The validity of the generalized model is demonstrated by comparing its displacement responses with the measured asymmetric responses obtained for magnetostrictive actuators under input frequencies of 10-100 Hz. The results suggest that the proposed rate-dependent Prandtl-Ishlinskii can effectively characterize hysteresis properties of the magentostrictive actuators under different excitation frequencies.