Research On Driving System Of Giant Magnetostrictive Micro-Displacement Actuator

Micro displacement drive system is widely used in aerospace,medical equipment,precision machine tools and other fields.Giant magnetostrictive material(GMM),as a new type of intelligent material,has bidirectional reversible magnetomechanical energy transfer effect,and has the advantages of large strain,high energy density,large bearing capacity and low-pressure driving.It is a kind of micro displacement driving material with wide application prospect.Among them,Galfenol alloy,as a new type of giant magnetostrictive material,requires low magnetic induction,good tensile strength and processing performance,which is of great significance to further expand the application range of micro displacement drive system and improve its performance.In this paper,Galfenol alloy is used as magnetostrictive material to study a single degree of freedom micro displacement driving technology and its driving characteristics.Based on the elastic theory of cubic crystal,the magnetostrictive effect,magnetization process and hysteresis characteristics of GMM are analyzed.On the basis of theoretical analysis,a kind of giant magnetostatic actuator(GMA)based on Galfenol alloy is designed.The mechanical structure and magnetic circuit of open GMA are designed,the structural parameters of magnetizing coil are calculated,and the excitation magnetic field is simulated.The influence of stress on the magnetostrictive deformation of Galfenol alloy is discussed,and an external preload mechanism is realized.The driving circuit of GMA is designed and manufactured.According to the hysteresis characteristics of Fe GA alloy,Preisach model is used to study the hysteresis characteristics of GMA drive.The Preisach models of density function method and Everett function method are implemented respectively,and the two methods are simulated and compared.The driving device is set up,the return error data of GMA driving is collected,and the Preisach model is used to model and simulate.The maximum error between the simulation result and the real value is 2.88%.A single degree of freedom micro displacement drive control device is built,and the displacement drive and performance test experiments are completed.The results show that the saturation magnetostriction of Galfenol alloy increases from 380 ppm to450ppm when the applied prestress increases from 0mpa to 15 MPa.Using alternating current as the input of micro displacement drive device,the relationship between signal frequency,amplitude and output displacement is analyzed through experiments.When the input signal frequency is lower than 4 Hz,the average maximum output displacement is 26.3μm,and the maximum difference of output displacement in different periods is less than 0.1 μm.