声发射与EMD相结合的埋地水管泄漏定位检测

Measurement of leak location in buried iron water pipe with acoustic emission and EMD

针对运用水管泄漏定位方法的直接相关法受到噪声和声传播方式的影响,使其定位精度低的问题,提出了一种基于经验模态分解(empirical mode decomposition,EMD)与能量特征提取相结合的水管泄漏定位.该方法用声学传感器采集数据,通过分析噪声和声传播方式对直接相关法定位的影响,采用EMD分解将采集数据分为不同的频段,再基于能量特征的方法从其中提取有用的频段作互相关分析,通过比较相关系数来确定泄漏位置.仿真和实验表明,该方法消除了直接相关法的缺点,提高了定位精度.

A method based on empirical mode decomposition （EMD） and power feature extraction to locate the leak point was presented to overcome the disadvantage of location precision being low （affected by the noising and the propagation modes of sound） of direct cross-correlation method to pinpoint the leak point. This method based on data sampled by acoustic emission sensors, analyzed the direct cross-correlation affected by the noising and the propagation modes of sound, and decomposed the signal into a series of frequency bands, from which a few useful frequency bands were selected by power feature extraction, and then the leak point was determined by comparing the correlation coefficient. Simulation and experiments indicated that the method presented above eliminated the disadvantages of direct cross-correlation and im： proved the precision of location.