Infrasonic wave method for pipeline leakage locating based on EEMD filter and time delay estimation

A leakage detection and locating method was proposed against the problems of noise interference and locating error in infrasonic gas pipeline leakage detection. The method, in which the empirical mode decomposition(EMD) was taken as the basis and the ensemble empirical mode decomposition(EEMD) was adopted to improve the mode mixing phenomenon, was used to set up a correlation analysis-based signal filtering method. Based on the generalized crosscorrelation algorithm, the quadratic correlation time delay estimation algorithm was used to improve the leakage locating accuracy. The filtering results and locating accuracy were tested and verified with field data. The results show that this method is capable of effectively filtering the noise, improving the signal-to-noise ratio, and permitting the locating accuracy to meet the engineering demands.