埋地输气管道泄漏振动声源双阵列定位方法

Dual-array localization of vibroacoustic source for leaks in buried gas pipelines

为实现埋地输气管道泄漏的精确定位,提出基于特征空间波达方向估计的双阵列定位方法,使用地表加速度传感器阵列检测泄漏振动声波信号,标记地面检修点并获取泄漏源埋深。为排除实验环境有限空间混响干扰,引入最小方差无失真响应波束形成算法进行阵列信号空域滤波。实验土壤条件下,测得泄漏信号频率为200~700 Hz,P1波波速为1108 m/s。混响滤波后不同位置阵列可精确估计泄漏源方向,并在-3 dB信噪比条件下保持低于1°的均方根误差。当泄漏源位于第2组阵列的前方,-3 dB信噪比下标记点距离、泄漏源深度的计算误差分别低于0.06 m、0.04 m,可通过适当调整阵列位置实现精确定位。与单阵列定位法对比,双阵列定位法对远场泄漏源的定位精度更高,定位误差平均降低了79.45%,有助于排查、确认埋地输气管道微泄漏点,保障管道安全运行。(图15,表2,参26)

To accurately locate leaks in buried gas pipelines,a dual-array localization method of eigenspace-based DOA estimation was proposed to detect the leak-induced vibroacoustic signals with the ground-mounted accelerometer array,identify the ground markers and obtain the depth of the leak source.The minimum variance distortionless response beamforming algorithm was introduced to conduct spatial filtering for the array signal,so as to eliminate the reverberation interference in the finite experimental space.Under the experimental soil conditions,the frequency of the leak signals ranges from 200 Hz to 700 Hz and the P1 wave speed is 1108 m/s.After filtering on the reverberation signal,the source directions can be accurately estimated with the arrays at different locations,for which the root mean square error is kept lower than 1°at the SNR of-3 dB.When the leak source is located in front of the second array,the calculation errors of the marker distance and leak source depth are found lower than 0.06 m and 0.04 m respectively at the SNR of-3 dB,and accurate localization can be achieved by properly adjusting the array location.The locating accuracy of the dual-array localization method is higher than that of the single-array locating method,with the localization error reduced by 79.45%on average,which is helpful to identify and verify the microleak points of buried gas pipelines,and ensure the safe operation of pipelines.(15 Figures,2 Tables,26 References)