Dynamic modeling and adaptive vibration control study for giant magnetostrictive actuators

Giant magnetostrictive actuators (GMA) used in vibration control and high precision positioning control have been studied widely in last decade. Recently, although many researchers commit themselves to modeling giant magnetostrictive actuators, there is still lack of simplified model of analyzing nonlinear properties to deal with the problems on active vibration control with giant magnetostrictive actuators. In this paper, a nonlinear constitutive model of a giant magnetostrictive actuator is put forward for the application of effectively suppressing vibration. The nonlinear constitutive model is established not only by combining linear constitutive equations with the Bouc–Wen equations but also by using Hamilton's principle and the assumed mode method to analyze the hysteresis phenomena and quadric frequency property in the giant magnetostrictive actuator. In addition, a minimum variance self-turning regulator (MVSTR) is incorporated into the design of a controller, which may be used in suppressing low frequency (≤5 Hz) and micron-level (≤5 μm) disturbances. In the end of this paper, some simulations are performed in LABVIEW and experimental control tests are implemented using a giant magnetostrictive actuator prototype. Both the numerical simulations and experimental tests results show that the amplitudes of disturbances may be reduced up to no less than 90% averagely in the whole sampling processes. This proves that the giant magnetostrictive actuator has not only the capacity of controlling low-frequency and micro-level vibration but also the notable effectiveness of active control by the adaptive regulator. Moreover, the minimum variance self-tuning regulator is testified as a feasible controller for vibration control in the paper.