高频磁致伸缩换能器谐振频率特性分析与控制

Analysis and control of resonance frequency characteristics of high-frequency magnetostrictive transducers

本文研究了工作温度和负载变化对换能器谐振频率的影响规律并设计了反馈控制系统以实现谐振频率跟踪。首先基于磁致伸缩换能器机电等效电路,推导了以工作温度T和负载F为自变量的谐振频率计算模型,搭建了温度可控、负载可调的谐振频率测试系统;然后对实验测试数据进行分段线性拟合和曲面数值拟合,得到了满足线性相关度和曲面拟合优度要求的谐振频率关于温度和负载变化的二元函数模型,进而确定了谐振频率计算模型的相关参数;最后依据计算模型设计了反映温度和负载变化的频率跟踪反馈控制系统并测试了换能器输出特性,结果表明换能器的振动加速度幅值平均提高了31.11%,且谐振频率能跟随温度和负载的变化而自动调整,实现高效率稳定运行。

This paper studies the influence rule of operating temperature and load changes on the resonant frequency of the transducer and a feedback control system is designed to realize the resonant frequency tracking.Firstly,the resonant frequency calculation model with operating temperature T and load F as independent variables is derived based on the electromechanical equivalent circuit of the magnetostrictive transducer,a temperature-controllable and load-adjustable resonant frequency test system is built;then,the methods of segmental linear fitting and surface numerical fitting are performed experiment on the tested data,and a binary function model of resonant frequency with respect to the temperature and load variables is obtained to meet the requirements of linear correlation and surface fitting goodness,and the relevant parameters of the resonant frequency calculation model are determined.Finally,based on the caculation model,a frequency tracking feedback control system reflecting temperature and load changes was designed and the output characteristics of the transducer were tested.The results show that the vibration acceleration amplitude of the transducer is increased by about 31.11%in average,and the resonant frequency could be automatically adjusted according to the temperature and load changes to achieve high efficiency and stable operation.