超磁致伸缩电—机转换器位移感知模型及滞环分析

超磁致伸缩电—机转换器响应快、可靠性高,但动态驱动时,因受磁滞、涡流等因素影响,输出位移的滞环较大。需要以准确的数学模型为基础,通过控制算法来补偿滞环,或通过优化其结构参数来降低滞环。通过实时测量超磁致伸缩棒上所绕线圈两端的感应电压和推导此感应电压与超磁致伸缩电—机转换器输出位移的关系,建立实时反映超磁致伸缩棒磁化状态的超磁致伸缩电—机转换器动态位移感知模型,并进一步推导出了超磁致伸缩电—机转换器输出位移的滞环与其结构参数的关系。通过与试验结果对比,当驱动频率小于300 Hz时,由所建模型计算出的位移峰—峰值的相对误差小于5.8%;通过仿真研究超磁致伸缩电—机转换器结构参数对输出位移滞环的影响,得出增加预压弹簧的刚度,可以降低动态驱动时的滞环。

Research on Displacement-sensing Model and Hysteresis Loop of Giant Magnetostrictive Actuator

Because the effect of hysteresis and eddy loss,the displacement’s hysteresis loop of giant magnetostrictive actuator with fast response and high reliability is serious.An accurate dynamic model is needed to compensate for hysteresis loop or used for decreasing hysteresis loop by structural optimization.By real time measuring the induced voltage of coil winded on giant magnetostrictive material rod and establishing the equations between the induced voltage and displacement of giant magnetostrictive actuator,a dynamic model which reflects magnetization of giant magnetostrictive rod is presented.And the relationship between the displacement’s hysteresis loop of giant magnetostrictive actuator and its structural parameters is derived.The comparison results of simulation and experiments show the error of peak-to-peak value of displacement is less than 5.8%,when the driving frequency is less than 300 Hz;the conclusion that the displacement’s hysteresis loop can be decreased by increasing preload spring’s stiffness by simulating the relationship between the displacement’s hysteresis loop of giant magnetostrictive actuator and its structural parameters.