Investigation Of Hysteresis Nonlinearity For Magnetically Controlled Shape Memory Alloy Actuators Based On Preisach Model

In recent years, intelligent materials are attracting more and more attention. As a newkind of intelligent material, magnetic shape memory alloy (MSMA) shows an interestingpotential in the area of smart actuators due to its outstanding performance. MSMA ownsboth shape memory effect and magnetic control shape memory effect. It has larger outputstrain than the shape memory alloy, and it also has the advantages of larger rapid frequencyresponse, larger efficiency and easier to control than the giant magnetostrictive material.Having these advantages, magnetic shape memory alloy will have a bright future.Compared with other intelligent materials, magnetic shape memory alloy has a shorthistory, and the research on magnetic shape memory alloy is rare. In this paper, investigationand analysis focus on the hysteresis nonlinearity effects. The actuator’s model and inversemodel are established, and high accuracy position control algorithms are proposed, aiming atimproving the control precision of the actuator.In this paper, the deformation mechanism of MSMA and the performance of materialare introduced. The Preisach model is established to describe the hysteresis nonlinearityeffects. And the recursive least square method, the weighted recursive least square methodand forgetting factor least square method are used to identify the weighting parameters of thePreisach operators. The experimental results show the validity of the proposed method.In this paper, an approximate algorithm of the inverse hysteresis model is established,and then the inverse model is used as a feed-forward controller to realize the feed-forwardcontrol of MSMA actuator. The experimental simulation results show that the feed-forwardcontrol can compensate the hysteresis nonlinearity effectively, and the proposed method canimprove the control accuracy.In order to further compensate the hysteresis nonlinearity, the PID hybrid control basedon the inverse Preisach model feed-forward compensation and fuzzy adaptive PID hybridcontrol based on the inverse Preisach model feed-forward compensation are proposed. The experimental simulation results show that the proposed control method can effectivelyeliminate the effect of the hysteresis nonlinearity.