超磁致伸缩换能器谐振频率自动跟踪方法

为了能有效地减小换能器的体积，实现同位控制及对换能器工作频率的自动调节，提高换能器的工作效率，提出了超磁致伸缩换能器的谐振频率自动跟踪方法。根据超磁致伸缩材料压磁方程，建立了超磁致伸缩换能器速度、阻抗及所受外力的自感知模型；分析了利用感知阻抗自动搜索谐振频率的工作原理，在无需安装检测谐振频率传感器的条件下，实现换能器谐振工作点的自感知，并能方便、快速地自动跟踪系统的谐振频率。在研制的实验装置上，比较分析了扫频方式和搜索感知阻抗方式跟踪谐振频率的一致性，验证了换能器谐振频率自动跟踪方法的可行性与正确性。

Method of Automatic Following Resonance Frequency for Giant Magnetostrictive Transducer

To decrease the transducer volume, enhance the collocation control, self-regulate the working frequency and improve the working efficiency of the transducer, the method of the resonance frequency automatic following for giant magnetostrictive transducer is presented. According to the piezomagnetic equation for the giant magnetostrictive material, self-sensing models of velocity, impedance and effected force for giant magnetostrictive transducer are set up. Without a fixing sensor of inspecting resonance frequency, the principle of automatic searching for the resonance frequency using the self-sensing impedance is analyzed, the working point self-sensing and the system resonance frequency automatic following in convenience and speediness are accomplished. The result of the transducer experiment equipment manifests that the method of the automatic following resonance frequency is feasible and proper by comparing the frequency sweeping mode with the searching self-sensing impedance mode.