电容式高频振动幅值测量方法研究  

Research on Measurement Method of Capacitive High Frequency Vibration Amplitude

作　　者：肖青伟 段发阶[1] 黄婷婷[1] 叶德超[1] 李杨宗 XIAO Qing-wei;DUAN Fa-jie;HUANG Ting-ting;YE De-chao;LI Yang-zong(Tianjin University,State Key Laboratory of Precision Testing Technology and Instruments,Tianjin 300072,China;Smartmens(Tianjin)Technology Co.,Ltd.,Tianjin 300380,China)

机构地区：[1]天津大学精密测试技术及仪器国家重点实验室,天津300072 [2]善测(天津)科技有限公司,天津300380

出　　处：《仪表技术与传感器》2020年第9期106-111,共6页Instrument Technique and Sensor

基　　金：天津市自然科学基金(17JCQNJC01100);装备预研领域基金(61405180505,61400040303);国家自然科学基金项目(51775377,61505140);国家重点研发计划(2017YFF0204800)。

摘　　要：针对超声疲劳试验中20 kHz以上的高频振动幅值的测量问题,提出一种电容式高频振动幅值测量方法,并构建了基于该方法的测量系统。文中以振动信号处理为主线,设计基于调幅式的振动解调电路,实现传感器信号的高精度解调;设计频率自适应数字滤波器实现解调信号的动态滤波;设计基于Hilbert变换实现数字包络检波器完成振动信号幅值的精确求解。对基于此方法测量系统的精度和测量范围进行了实验验证,实验结果证明,此系统具有较高的精度和较大的测量范围,其精度优于0.3%F.S.,振幅测量范围最大可至100μm,动态频响超过20 kHz。Aiming at the measurement of high frequency vibration amplitude above 20 kHz in ultrasonic fatigue test,a capaci-tive high frequency vibration amplitude measurement method was proposed,and a measurement system based on this method was constructed.In this paper,the vibration signal processing was taken as the main line,and the amplitude modulation based vibration demodulation circuit was designed to realize the high precision demodulation of the sensor signal.The frequency adaptive digital filter was designed to realize the dynamic filtering of the demodulated signal.Finally,based on the Hilbert transform,the digital envelope detector is used to accurately solve the amplitude of the vibration signal.The accuracy and measurement range of the measurement system based on this method were verified by experiments.The experimental results show that the system has high precision and large measurement range,and its accuracy is better than 0.3%F.S.,the amplitude measurement range can be up to 100μm,and the dynamic frequency response is over 20 kHz.

关 键 词：超声疲劳试验 电容传感器 高频振动 高精度解调 自适应动态滤波 幅值求解 

分 类 号：TP274[自动化与计算机技术—检测技术与自动化装置]