基于改进变分模态分解的供水管道单测点泄漏检测定位方法

Leakage Detection and Location Method of Single Measuring Point of Water Supply Pipeline Based on Improved Variational Mode Decomposition

为克服传统负压波技术用于供水管道泄漏检测定位时,只能对2个传感器之间的管段进行检测与定位的不足,将压缩波和流体波引入检测和定位过程中,同时为了提升漏点定位精度,提出一种基于变分模态分解和Teager能量算子相结合的泄漏初始时刻计算方法。该方法首先采用VMD将被测信号分解为多个IMF,再将各个IMF和参考信号进行互相关处理和均方差计算,建立目标函数;然后通过设定阈值剔除大部分噪声,并对经过初步去噪后的信号所对应的模态分量进行重构,最终实现信号降噪。为验证该方法的有效性,对不同材质的管道进行泄漏工况模拟仿真,其结果表明:该方法对泄漏初始时刻计算误差较小,漏点定位精度较高;对PVC管泄漏定位的相对误差为0.49%,对钢管泄漏定位的相对误差为0.14%。

In order to overcome the problem that the traditional negative pressure wave technology can only detect and locate the leakage in the pipe segment between two sensors,the compression wave and fluid wave were introduced into the detection and location process.At the same time,in order to improve the accuracy of leak location,a method of calculating the initial leak time based on variational mode decomposition and Teager energy operator was proposed.Firstly,VMD was used to decompose the measured signals into multiple IMFs.Then the IMF and reference signals were cross-correlated and the mean square error was calculated to establish the objective function.Secondly,the threshold was set to eliminate most of the noise,and the modal component corresponding to the signal after the initial denoising was reconstructed.Finally signal noise was reduced.In order to verify the effectiveness of the proposed method,the leakage conditions of pipelines with different materials were simulated.The simulation results show that the proposed method has less error in calculating the initial leakage time and higher accuracy in locating the leakage point.The relative error of PVC pipe leakage location is 0.49%,the relative error of steel pipe leakage location is equal to be 0.14%.