基于Chirp激励的管道污垢超声导波检测频率优化选择研究  

RESEARCH ON OPTIMAL SELECTION OF UITRASONIC GUIDED WAVE DETECTION FREQUENCY IN DIRT PIPES BASED ON CHIRP EXCITATION

作　　者：孙灵芳[1] 张颖 吴春迎[1] 朴亨 SUN LingFang;ZHANG Ying;WU ChunYing;PIAO Heng(School of Automation Engineering,Northeast Electric Power University,Jilin 132012,China;Energy Conservation & Measure-Control Center,Jilin 132012,China)

机构地区：[1]东北电力大学自动化工程学院,吉林132012 [2]吉林省节能与测控技术工程实验室,吉林132012

出　　处：《机械强度》2019年第3期594-599,共6页Journal of Mechanical Strength

基　　金：国家自然科学基金项目(51176028)资助~~

摘　　要：采用传统的单频信号作为污垢管道导波激励信号,须进行反复多频测试以确定最佳检测频率,存在一定盲目性以及时间、资源耗费等问题,提出一种宽单频转换算法,在采用宽频chirp信号作为污垢管道超声导波激励信号基础上,利用该算法对其响应信号进行后处理,可获得其频带范围内等同于单频信号激励时的响应,通过对比不同频率导波响应的能量分布及模态纯度确定最佳检测频率,并结合时频分析方法,根据污垢管道宽频响应能量分布情况快速确定合适的检测频率区间。仿真分析及实验研究表明:中心频率175 kHz最适合于所考察污垢管道导波检测,利用该方法确定污垢管道最佳导波检测频率的过程在减少采集时间的同时解决了多频测试的需要,为利用导波方法实现管道污垢由"点"到"线"的检测奠定了的基础。It is required to conduct repeated multi-frequency test to determine the best detection frequency when taking traditional tone burst as the guided wave excitation of dirt pipe,which had problems of blindness,time and resources consuming.A conversion algorithm from broadband chirp to tone burst was put forward based on broadband chirp guided wave excitation of dirt pipe.All tone burst responses in the broadband of chirp signal is similarly extracted during post-processing.The best detection frequency was determined through the comparing energy distribution and modal purity of the different frequency guided wave responses that it was calculated from the chirp response,and combined with time-frequency analysis method to determine the appropriate waveguide frequency interval according to the distribution of the response waveform energy of the dirt pipe.It had shown from simulation analysis and experiment studies that: the center frequency of about 175 kHz was the most appropriate for guided wave detection of investigating dirt pipe.The method could determine the best guided wave detection frequency of dirt addresses both test at multi-frequency and minimize acquisition time,which would lay a foundation for achieving guided wave detection from the ‘point’ to ‘line’ of the pipe dirt.

关 键 词：污垢检测 超声导波 chirp激励 时频分析 

分 类 号：TB559[理学—物理]