为了提高超磁致伸缩微位移变形控制的精度与实时性,针对一般超磁致伸缩微位移控制中存在的迟滞非线性问题,提出将超磁致伸缩材料(GMM)的磁感应强度作为反馈量构成闭环控制系统的方法.通过谐振电路测量探测线圈动态阻抗的方式,使得探测线圈阻抗的变化反映GMM内部变化的磁导率,从而计算获得GMM的磁感应强度.实验结果表明,当交变电流或直流电流通人励磁线圈时,通过谐振电路测量探测线圈动态阻抗获得GMM的磁感应强度,其平方值与GMM微位移变形始终保持良好的线性关系.
A closed-loop controlling method utilizing magnetic induction of giant magnetostrictive materials (GMM) as feedback quantity was proposed in order to improve the accuracy and realtime performance of the giant magnetostrictive micro-displacement controlling system, which can additionally overcome the nonlinearity hysteresis in giant magnetostrictive micro-deformation controlling system. A self-oscillation circuit was applied in order to test the impendence of the measuring coil, and the variation of GMM magnetic conductivity were showed by the variation of self-oscillation voltage, then the magnetic inductions of GMM can be calculated out. The squared value of GMM magnetic conductivity has a continuous favorable linear relation with micro-displacements by a series of dynamic and static experiments with AC or DC currents applied on the driving coil.