有限空间液态场中声发射信号时延估计方法

Time Delay Estimation Method of Acoustic Emission Signals in Confined Underwater Space

石油储罐罐底腐蚀的定位可利用声发射信号的时延估计实现,但在有限空间液态场中信号的传播会产生严重的多途效应,对准确进行时延估计产生不利影响。提出一种基于信号截取的广义互相关时延估计方法。采用曲线拟合法对每路传感器采集信号进行波达时刻估计,然后进行信号截取,对两路传感器截取信号进行基于相位变换的广义互相关,实现信号的时延估计。实验结果表明,该方法能有效克服多途干扰,提高时延估计性能。

Time delay estimation（TDE） of acoustic emission signals can be used to locate the corrosion in oil storage tank bottom.Multipath propagation is inevitable and affects the accuracy of TDE in a confined underwater space.A new time delay estimation method based on generalized cross-correlation with truncated signals was proposed.Curve fitting was used to estimate the time of arrival of the received signals.The signals were truncated to suppress multipath and generalized cross-correlation based phase transform（PHAT） was applied to estimate the time delay.Experimental results show that the method can reduce the effect of multipath effectively and improve the performance of TDE.