Research On Leak Detection And Location Method Of Water Supply Pipeline Based On Acoustic Signal

At present,the problem of water shortage is becoming more and more serious.About3.6 billion people in the world live in water-deficient areas.However,the leakage of water resources is serious in the process of distribution and utilization.On average,35% of the water resources are lost in the process of distribution and utilization.The annual leakage in my country alone is nearly 10 billion tons.This not only leads to a large amount of water resources being wasted for no reason,but also causes huge economic losses,and affects the normal domestic water demand of residents.At the same time,the leakage point of the pipeline is also a potential intrusion point of pollutants,which is easy to contaminate drinking water and may endanger the life safety of residents.Therefore,quickly and accurately locating the leakage location is of great significance for saving water resources and ensuring water safety for residents.Traditional leak detection methods rely on passive manual inspection,which is time-consuming,labor-intensive and inefficient.Pipeline leak detection and location methods based on acoustic signals are widely used due to their high accuracy,simple operation,low cost,and easy implementation.However,the detection method based on acoustic signal is easily disturbed by environmental noise,and the leakage signal is a non-linear and nonstationary signal,which is difficult to process,which leads to a decrease in the accuracy of pipeline leakage detection and location.In view of the above problems,this paper carries out the following researches from two aspects of pipeline leak detection and pipeline leak location.1.Research on pipeline leak detection method based on Extreme Learning Machine（ELM）.In this paper,a multi-feature combination pipeline leak detection method is implemented.First,build an acoustic signal acquisition system to collect three types of acoustic signals,such as normal operation of the pipeline,leakage and artificial percussion.Then,the multivariate Variational Mode Decomposition（MVMD）algorithm is used to preprocess the acoustic signals of different working conditions,and the average value,kurtosis,impulse factor,dispersion entropy and other features are selected to construct feature vectors.Finally,using The extreme learning machine classifies the pipeline conditions.The experimental results show that the average recognition rate of this method can reach 98.88%.2.Research on cross-correlation pipeline leak location method based on acoustic signal.In this paper,a cross-correlation leakage localization method based on MVMD denoised signal is implemented.First,by comparing the spectral characteristics of the leaked and non-leakage acoustic signals,the characteristic frequency band of the leaked signal is determined.Then,the leaked signal is decomposed using the MVMD algorithm to obtain multiple different Intrinsic Mode Function（IMF）components,and select the effective component according to the correlation coefficient between the IMF component and the signal in the characteristic frequency band.Finally,use the selected effective components to reconstruct the signal,analyze the cross-correlation of the reconstructed signal to obtain the delay time,and determine the location of the leakage point of the pipeline.The experimental results show that,compared with the pipeline localization method based on Variational Mode Decomposition（VMD）combined with correlation coefficient and the pipeline localization method based on Empirical Mode Decomposition（EMD）combined with correlation coefficient,this method has higher accuracy.The average relative positioning error is within 2% under a variety of different experimental conditions.3.Design and implementation of pipeline leak detection and location system.First of all,the demand for leak detection and location system of water supply pipeline is analyzed.Then,the overall functional structure of the system is determined according to the requirements.On the basis of the research on leak detection and location of water supply pipelines,each functional module of the leak detection and location system of water supply pipelines is realized by using the mixed programming method of MATLAB and Qt.Figure [46] table [14] reference [52]...