第37卷第9期 2016年9月
仪器仪表学报 Chinese Journal of Scientific Instrument
气体管道泄漏模态声发射时频定位方法
李帅永，王鹏飞，严冬，王平，黄心成
（重庆邮电大学工业物联网与网络化控制教育部重点实验室重庆400065）
Vol. 37 No. 9 Sep.2016
摘要：针对声发射信号频散特性导致基于时延估计的气体管道泄满定位误差大的问题，提出一种基于模态声发射时频分析的泄漏定位方法。该方法采用平滑伪Wigner-Ville时频分布对两泄漏信号的互相关函数进行时频分析，利用互相关函数的时频谱可同时提取泄漏信号的时间延迟和与之对应的频率；然后根据泄漏声发射信号的主导模态的频散曲线即可确定该频率对应的声速，利用实时确定的声速和时间延迟并根据两传感器之间的距离即可确定泄漏点的位置。实验结果表明，采用时频分析的气体管道泄漏定位误差与互相关相比减少了6倍。所提出的模态声发射时频定位方法能有效抑制泄漏信号的频散，提高泄漏信
号的相关性，从而更适合用于声发射管道泄漏定位。关键词：泄漏定位；气体管道；模态声发射时频分析
中图分类号：TN911.7TH86
文献标识码：A
国家标准学科分类代码：510.40
Leaklocation ingaspipelineswithtime-frequency analysisof modal acoustic
emission using smooth pseudo Wigner-Ville distribution
Li Shuaiyong, Wang Pengfei, Yan Dong, Wang Ping, Huang Xincheng
( Key Laboratory of Netaork Control & Intelligent Instrument, Ministry of Education, Chongqing University of Posts and
Telecommunications，Chongqing 400065,China)
Abstract : Considering the time-delay-based leak location errors are large due to the dispersions of gas-leak-induced acoustic emission, leak location based on modal acoustic emission time-frequency analysis is presented. In the scheme , the correlation function is analyzed with the smooth pseudo Wigner-Ville distribution. The peak frequency and peak time are extracted simultaneously from the time-frequency distribution and the peak time is the time delay between the AE signals collected on either sides of a leakage. The acoustic speed can be determined by substituting of the peak frequency into the dispersive curve of dominant mode in leakage-induced AE signal. The leakage can be located with the time delay, the frequency-dependant acoustic speed of real-time determination and the distance between two acceleration sensors. The proposed scheme is experimentally validated in leak location of gas pipelines and the experimental results demonstrate that the average relative leak location errors are reduced by six times compared with the commonly used correlation-based leak location method. The research results also indicate that the time-frequency based leak location method can suppress the dispersions of leakage-induced AE signal and strengthen the correlation of the leakage-induced AE signals. Therefore , the proposed time-
frequency based leak location method is more feasible for improving leak location in fluid-filled pipelines with the AE technique. Keywords: leak location; gas pipeline; modal acoustic emission; time-frequency analysis
等)输运工具，由于腐蚀、老化、第三方破坏等原因，管道
1引言
管道是一种高效便捷的流体（天然气、石油、自来水
收稿目期：2016-01
Received Date: 2016-01
泄漏事故时有发生。管道泄漏不仅造成资源浪费、环境污染，甚至产生火灾、爆炸等恶性事故，给人们的生命财产造成严重的威胁。声发射技术作为一种实时在线的
*基金项县国塞高技术研究发展计划（863计划）课题（2015AA043801）、重庆市基础与前沿研究计划项目（cstc2015jcyjA40010）、重庆市教委科学技术研究项教据500423）、重庆邮电大学科研启动基金（A2015-13）、重庆邮电大学青年科学研究项目（A2015-66）资助