Leakage locating method combining self-adapting threshold value leak detection and multi-dimension fast delay time search

A leak positioning method combining self-adapting threshold value leak detection and multi-scale rapid time delay search belongs to the malfunction diagnosis technology field of oil (gap) pipeline, wherein pressure data at both ends of the pipeline and standard error of re-constructing signal difference value of the data based on orthogonal wavelet transformation de-noising process multiplying coefficient as threshold values at both ends. If average values before or after catastrophe point when the pressure at both ends reduces exceed the threshold value, judging that there is leak and positioning: calculating approximate wavelet transformation coefficient of pressure data at both ends, initializing searching interval, calculating a signal time delay value corresponding to approximate wavelet transformation coefficient in the searching interval from maximal scale N; converting the time delay value under scale N to that under N-1 by geometric proportion relation; updating the searching interval, repeating abov