Active vibration control under the actuator with magnetic hysteresis loop

Multiple degree-of-freedom (DOF) vibration isolation is essential for precision control of space-borne structures and weapon systems. Experimental results are described in which six magnetostrictive TbDyFe actuators were used in the capacity of a cubic configuration Stewart platform and a high performance computation control system and an adaptive real-time control algorithm was used. A new design and analysis of actuators employing magnetostrictive material TbDyFe is presented. The nonlinear constitutive relation for magnetostrictive materials actuators is presented that includes nonlinear coupling effects changing with frequency and magnetic field applied on TbDyFe rod. Since the magnetostrictive actuator is a nonlinear plant with magnetic hysteresis loop, its multiple frequency active vibration control is more complicated. In this paper, a Simple Hyperstable Adaptive Recursive Filter (SHARP) algorithm based on nonlinear model is proposed. The nonlinear model of magnetostrictive actuator is obtained by using radial basis neural network. The experimental result show that the proposed approach is real-time efficient. An attenuation of about 30dB is achieved. The algorithm is also suitable as a reference to the stabilizing control of a class of nonlinear system with magnetic hysteresis loop.