小波Semisoft阈值函数在输油管道泄漏信号处理中的应用

721200711167121819(2007)2125658204ScienceTechnologyandEngineeringVol.7No.21Nov.2007Z2007Sci.Tech.Engng.Semisoft((),257061),,,(semisoft),,,TN911.72;A2007723:(1976),,,,,,:E_mail:[e-mail],SCADA,,,,,,,,,,[1],,,,,,,1:x(i)=f(i)+e(i);i=1,2,,N(1)(1)x(i),f(i),e(i),,Nx(i)f(i),,,,;,(1),X,D1A1,A1D2A2,()()(),D1,D2,D3,,,,,,,;,,[2]1:(1),;(2),,,;(3)2Donoho[3],NX(N=2J),L(0LJ)(){VL,k;k=1,,2L},{wj,k;j=L,L+1,,J-1;k=1,,2L},N,VL,k=2logN,w1,k:(1),,0wj,k=wj,k,wj,k0,wj,k(2)(2)wj,k=sgn(wj,k)(wj,k-),wj,k0,wj,k(3),,0(3),Garrotewj,k=wj,k-2wj,k,wj,k0,wj,k(4),wj,k,,,,;,;,,,,,(semisoft)[4],wj,k=0,wj,k?1sgn(wj,k)2(wj,k-1)211wj,k2wj,k,wj,k2(5)1wj,k2,(5);|wj,k|2,(5)1=2,;2=,,12,,,,956521,:Semisoft3,,11QiPiQoPoQ1,,12.83km,,,,sym8,,23(),,semisoft,,,,24,,:,,,,,,semisoft,,0665731..:,19952.Matlab.:,19993DonohoDL,JohnstoneIM.Idealspatialadaptionviawaveletshrink2age.Biometrika,1994;81:4254554DonohoDL.De2noisingbysoft2thresholding.IEEETransonInfor2mationTheory,1995;41(3):613627ApplicationoftheWaveletSemisoftThresholdintheOilPipelineLeakageSignalsWULi2qing,LOUSheng2nan(InformationandControlEngineeringCollege,ChinaUniversityofPetroleum,Dongying257061,P.R.China)[Abstract]Becauseofthenoiseintheoilpipeline,thewaveletsemisoftthresholdmodelisutilizedtodenoisethepipelineleakagesignalstoimprovethehighsensitivityofleakdetectionandlowpercentoffalsealarmoftheleakagedetectionsystem.Comparingthedenoisingeffectwithhardthreshold,softthresholdandGarrotethreshold,theresultindicatesthatthesemisoftthresholdmethodisthemoreeffectivemethodinoilpipelinedenoising.[Keywords]waveletsemisoftthresholdmodelleakagedetectiondenoisingmethod166521,:Semisoft