Application of VMD in Pipeline Leak Detection Based on Negative Pressure Wave

Abstract

Leakage problems are common in the water supply pipeline system, which will threaten the health of residents and cause economic losses. Negative pressure wave (NPW) technology calculates the time difference through the inflection point to locate the leak. However, due to the nonlinear and nonstationary characteristics of the pressure signal, it is difficult to obtain an accurate inflection point of the NPW by the traditional method. Therefore, the advantages of applying variational mode decomposition (VMD) in NPW technology are explored. Firstly, the correlation coefficient and permutation entropy (PE) are used for effective intrinsic mode function (IMF) component selection and parameter optimization. Thus, an adaptive denoising method based on VMD (AD-VMD) is presented. Then, to effectively separate the detail features of the NPW, a novel inflection point extraction method based on VMD (IPE-VMD) is proposed. Simulation and experimental results show that AD-VMD can effectively suppress noise interference and conserve the mutation characteristic of the leakage. IPE-VMD can obtain a distinct maximum peak at the inflection point and has good robustness to noise interference. This method can calculate the time difference precisely and stably. In addition, the accuracy of the leak location is verified. The average relative positioning error is 5.13%.

Denoising Method of Pipeline Leakage Signal Based on VMD and Hilbert Transform

“…Due to the different spacing between the leakage point and the sensors located upstream and downstream of the pipeline, there is a time gap between the leakage vibration acoustic signal and the upstream and downstream sensors. The location of the leakage point can be obtained by the length of the pipeline, the speed of the vibration sound wave, and the time gap of the propagation [24].…”

“…Equation ( 1) is the basic formula based on delay location. Both the negative pressure wave techniques used in reference [24] and the acoustic emission technique used in this paper are developed based on this principle. In the research process of reference [24], Liu et al collect the pressure signal in the water supply pipeline through the pressure sensor, and the leakage will trigger the negative pressure wave and thus generate the pressure abrupt inflection point.…”

“…Both the negative pressure wave techniques used in reference [24] and the acoustic emission technique used in this paper are developed based on this principle. In the research process of reference [24], Liu et al collect the pressure signal in the water supply pipeline through the pressure sensor, and the leakage will trigger the negative pressure wave and thus generate the pressure abrupt inflection point. Liu et al study the negative pressure wave signal denoising method to achieve the accurate extraction of the inflection point, so as to improve the calculation accuracy of Δt in formula (1), and finally improve the positioning accuracy of the leakage point.…”

Study of a Machine Vision Approach to Leak Monitoring of a Marine System

“…Li et al [4] used a negative pressure wave attenuation algorithm for pipeline leak location that depends on pressure changes. Liu et al [5] introduced a new intrinsic permutation entropy method based on variational mode decomposition (VMD) to suppress noise disturbances and maintain the mutation characteristics of the leakage to locate pipeline leaks. Hardware-based methods typically rely on the use of sensor modules to measure pressure with low energy consumption, and specialized hardware devices can be applied to reduce energy consumption and provide higher efficiency through a highly optimized design compared to general-purpose computing devices.…”