关键词: 管道, 泄漏定位, 变分模态分解(VMD), 相对熵, 互时频

Abstract: In order to reduce pipeline leakage positioning error, so as to timely deal with pipeline leakage and prevent accidents, a pipeline leakage location method based on relative entropy analysis of VMD components was worked out. In the process of working out it, VMD was used to decompose the leakage signal into multiple components, the relative entropy analysis adaptive selection method was used to remove the non-leakage signals mixed with the pipeline leakage signal and obtain the best observation signal. Then, pipeline modal acoustic emission theory and generalized S-transformation time-frequency analysis were used to reduce the effect of the dispersion of the leak acoustic emission signal on location, and the delay and sound velocity of the leak signal were obtained accurately. Finally, the leak location was calculated by the pipeline leakage time difference positioning formula to achieve accurate positioning of the pipeline leakage. The results show that the method can realize the precise location of pipeline leakage points, and that the positioning accuracy is significantly improved compared with those by the direct mutual time-frequency analysis method and the correlation coefficient analysis method.

Key words: pipe, leakage location, variational mode decomposition(VMD), relative entropy, cross time frequency spectrum