Modelling and compensation of hysteresis for magnetostrictive actuators

The paper proposes the compensation of the hysteretic behaviour of an actuator constituted by a Terfenol-D magnetostrictive material to enhance the performance of a typical control scheme for vibration suppression. Hysteresis is modelled by the application of the classical Preisach model whose identification procedure is performed by the adoption of fuzzy approximators. This allows to reconstruct analytically either Everett integrals and the Preisach distribution function, without any special smoothing of the measured data, thanks to the filtering capabilities of the fuzzy interpolators. Moreover, the idea of compensator for operators with memory is also described in detail and the concept of pseudo-compensator is introduced. The latter operator allows to approximate the inverse of a given Preisach-like operator and then to easily compensate hysteresis and nonlinearity of a real magnetostrictive actuator.