Noise Reduction Method of Pipeline Leakage Signal Based on Variational Mode Decomposition

The noise reduction of the pipeline leak signal is the key to precisely locate the leakage point. However，the signal has non-stationary and non-linear characteristics，and the traditional method has a limited denoising effect on this type of signal. In order to effectively eliminate noise and improve the accuracy of leak location，an adaptive noise reduction method based on variational mode decomposition（VMD）is proposed. Initially，the effective intrinsic mode function（IMF）is screened by the correlation coefficient to realize the signal reconstruction. Then，according to the minimum value of the information entropy of the reconstructed signal，the optimal number of decomposition layers and the optimal denoising signal of VMD are obtained；Finally，the leakage location is realized by the theory of negative pressure wave. A pipeline leakage experiment system is built to verify the presented method. The results demonstrate that the developed method can effectively suppress noise，retain the waveform characteristics of the signal，and identify a distinct inflexion of the negative pressure wave. The minimum relative error of positioning is 0.9% and the maximum is 3.75%. Compared with the traditional method，the presented method has higher positioning precision and more stable results. © 2023 Nanjing University of Aeronautics an Astronautics. All rights reserved.