Investigation Of Controlling Technique For Giant Magnetostrictive Actuator On The Basis Of Preisach Hysteresis Model

The giant magnetostrictive actuator (GMA) is a new device, using a giant magnetostrictive material as a actuating component. It characterizes large displacement, high force, rapid response, wide range of temperatures and low voltage operation and can be applied in ultra-precise machining, robotics, and vibration control, etc. However, because of the strong hysteresis of the giant magnetostrictive material and the driving magnetic structure, the output displacement of an actuator possesses strong hysteresis, poor repeatability, and severe nonlinearity, which restrict the positioning precision of an actuator and hamper its wider applications in many fields.Firstly, giant magnetostrictive materials and their application are introduced, then the models and control technique for an actuator are summarized.The models of GMA, aimed at GMA's hysteresis, have been founded according to Preisach theory. The experimental results verify that the hysteresis model of GMA can describe the hysteresis nonlinearity exactly. Based on the model, the inverse model of GMA is deduced. a feed-forward controller is designed to compensate the hysteresis nonlinearity. On the basis of feed-forward control, an control technique with feed-forward controller and feedback controller is designed, it can adjust controller parameter through take full advantages of feed-forward's"quickly compensate"and feedback control's "eliminate error"to improve the control precision of GMA.The controller system of GMA based on TMS320F2812 is designed, including the A/D module, D/A module, clock circuit etc. compiled software of the system in the CCS. On these basis, the control system of GMA is built to investigate the static state and dynamic characteristic of GMA. The experimental results verify that feed-forward can compensate thehysteresis nonlinearity effectively and the responding speed of GMA becomes sooner. The control precision of GMA is largely improved.At the last part of this paper, the main contents are summaried and the suggestion of the probable further research work in this region is given.