The Damage Monitoring System Of Buried Pipeline Based On Virtual Instrument Technology

Pipeline transportation is one of the five main transportation ways and it plays amajor role in civil water supply system. As water resource decreasing day by day, thequality of water supply pipelines becomes an increasingly important issue. However,pipeline accidents have frequently occurred over the years, especially the moreseriously intended mangle which has caused huge waste of the water resource. Thus adevice is needed urgently which can not only monitor the mangle of the pipeline, butalso locate the water leak points in pipelines.Extensively consulting the related references inland and overseas in the real timedetection of the water leakage of buried pipelines, the system brings forward acousticemission measurement detecting the mangle signal. In order to achieve the accuracyrequirement, writer has carried on the data acquisition card matching and correlateddebugging of the important instrumentations, and then design a pipeline detectionsystem based on virtual instrument technology. Under laboratory conditions wesimulates the normal circulate and occurrence breaks of the pipeline, then monitor thedamage activities of pipeline and locate the leak points.The main work and innovative methods are listed as follows:(1) Design a monitoring system of mangle activities of buried pipelines based onvirtual instrument technology. Based on the principle of the mangle pipelines detectionand related signal process theories, we choise acoustic signals as research object,decrease the SNR by a modified denoising algorithm, then monitor and locate thepipeline breaks. Finally, we do some experiments in different damage situation andcarry on the analysis and comparison for the test results.(2) A method based on Independent Component Analysis (ICA) to denoise theleak signals of pipeline is presented to overcome the disadvantage of leak signals thatthey are always very weak and strongly affected by the background noises. Modifiedthe FastICA algorithm by a non-gaussianity measure based on characteristic function,and then proposed a signal-noise analysis method base on modified algorithm, whichcan be applied to denoise the leak signal of pipeline effectively. Simulation and experiments indicated that the denoising method based on ICA can get highersignal-noise rate (SNR) and better correlation coefficient by comparing with waveletdenoising method, thus improved the precision of water pipe leak location.(3)Design and develop the software part of the monitoring system based ongraphic program tool LabVIEW. The process of the designing the interface becomessimpler owing to the virtual instrument which resorts to the advantage of LabVIEW,including lots of ready signal process modules, such as DAQ modules, signaldenoising module, leak location module and so on.