包带连接建模与非线性动力学特性分析(3)

informationentropyforabnormalvibrationeventsofapetroleumpipelineZHANGJing chuan,ZENGZhou mo,LAIPing,FENGHao,JINShi jiu

(StateKeyLaboratoryofPrecisionMeasurementTechnologyandInstrument,TianjinUniversity,Tianjin300072,China)

Abstract: Arecognitionmethodforsafety detectioneventsofoilandgaspipelinesbasedonthewaveletenergy

spectrumandthewaveletinformationentropywasstudied.ItwasusedinadistributedopticalfiberoilandgaspipelinesafetydetectionsystembasedontheprincipleofMach Zehnderopticalfiberinterferometerforthesafetyofoilandgaspipelines.Inthispre warningsystem,anopticalcablewaslaidalongapipelineinthesameditchandthreesingle modeopticalfibersintheopticalcablebuiltupadistributedmicro vibrantmeasuringsensor.Thevibrationsignalcausedbyleakageandotherabnormaleventscouldbedetectedbyusingthesysteminreal time.Thedetectionsignalsofabnormale ventsweredecomposedintosub signalsindifferentfrequencybandsbyuseofwavelettransformationwithmulti resolutionanalysis.Thus,bothfrequencybandenergyfeaturesandwaveletinformationentropyoftheabove mentioneddetectionsig nalswereextracted;thesystemcouldrecognizeabnormalintrusioneventsoccurredalongthepipelinethroughthewaveletenergyspectrumandthewaveletinformationentropyinreal time.Finally,theexperimentaldataobtainedatGangZaoproductpipelinewereusedtoevaluatetheproposedmethodandtheoverallrecognitionaccuracyratereached98.5%,itverifiedthefeasibilityandeffectivenessofthismethod.Keywords:petroleumpipeline;distributedopticalfibersensor;waveletenergyspectrum;waveletinformationen tropy;patternrecognition(pp:1-4)

Modelingofamarmanclampbandjointanditsnonlineardynamicanalysis

112

BAIShao jun,WEIFei,ZHENGGang tie

(1.HarbinInstituteofTechnology,Harbin150001,China;2.TsinghuaUniversity,Beijing100084,China)

Abstract: Amarmanclampbandjoin,twhichismadeofseveralV segmentsheldwithtwotensionedstraps,iswidelyusedintheaerospaceindustrytoconnectanddisconnectrocketsandsatellites.Toinvestigatethedynamiccharac

teristicsofamarmanclampbandjoin,tthecontactforcesbetweenthecomponentsofthemarmanclampbandjointandtherelationshipbetweenthecontactforceswereanalyzed.Byreplacingthesecontactforceswithequivalentelementnodeloads,themarmanclampbandjointwasincorporateintotheformalfiniteelementmodeloftheglobalstructure.Thedy namicequationsofthestructurecontainingthemarmanclampbandjointwerenonlineardifferentialequationssolvedusingtheNewmark sdirectintegrationmethod.Finally,astandardmarmanclampbandjointwasanalyzedasanexampletoveri fytheproposedmethod.Thenonlineardynamiccharacteristicsofthemarmanclampbandjointandtheinfluenceofthepretensionwereanalyzed.

Keywords:marmanclampbandjoin;tsatellite;nonlineardynamics

(pp:5-10)

BearingfaultdiagnosiswithaMSVMbasedonagarchmodel

TAOXin min,XUJing,YANGLi biao,LIUYu

1

2

1

1

(1.CollegeofInformationandCommunicationEngineering,HarbinEngineeringUniversity,Harbin150001,China;2.DepartmentofMathematicsandMechanics,HeilongjiangInstituteofScienceandTechnology,Harbin150027,China)

Abstract: Inbearingfaultdetectionapplication,tosolvetheproblemsofdifficultlydescribingsignalcharacteristicsusingauto regressive(AR)modelsduetothesignal snon stationarycharacteristics,anovelone classdiagnosismodelu singamulti classsupportvectormachines(MSVM)basedonageneralizedautoregressiveconditionalheteroscedasticity(GARCH)modelwaspresentedhere.TheGARCHmodelwasemployedtodescribedifferentbearingvibrationsignals,theparametersofthegenerateddifferentmodelswasusedasthesignal diagnosischaracteristicsandconsequentlytheclas sifierbasedonMSVMwasestablished.Theexperimentsshowedthattheproposedapproachcanefficientlyovercomethe.diththe