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1、江南大學碩士學位論文概率PCA多元統(tǒng)計方法在過程監(jiān)控中的應用研究姓名:楊沛武申請學位級別:碩士專業(yè):檢測技術與自動化裝置指導教師:劉飛20080601AbstractAfterlongtimerunning,therearesomechangesinanyproducingsystem,whichwillunavoidablyinfluencethequalityofproductsandevenresultingreataccidents.Therefore,thetraditionalmethodsent
2、irelybasedonmanpowerareoutdatedandcannotsatisfythecomplicateddesireofqualitycontr01.Havingnouseofcomplexmechanismmodel,multivariablestatisticalprocessmonitoringmethodcanmonitorprocessthroughextractingimportantinformationfromrawdatausingstatisticalmethodandt
3、hentransformingthemintoseveralsignificativeindices.Themethodnotonlytakessufficientuseoftheexistinginformationandiswellrealizable,butalsogreatlyreducestheprocedureofprocessmonitoringsystem,whichhasbeendevelopedmorethanthirtyyears,inwhichlotsofresearchresults
4、havebeenacquiredandappliedwidely.Probabilisticprincipalcomponentanalysis(PPCA)firstlyassumethedistributionoflatentvariablesanderrorvector,secondlyevaluatethegenerativemodelbytheexpectationandmaximization(EM)algorithm,SOitcalldetectfaulteffectivelyandperform
5、son—linefaultidentification。whichmakeitattractivebothinindustryandacademia.HoweverPPCAisalinearway,thepreconditionsofitsapplicationarethatprocessarenormallydistributedandnoauto-correlationamongthem.Butmostofindustrialprocessarecomplicatedandalwaysviolatethe
6、preconditions,SOthePPCA.basedmethodbehavesunsatisfactorily.AimingatthedisadvantagesofthePPCA—basedmethod,themaincontributionsareasfollows:1.Thedissertationproposesallimprovedmonitoringwaywhichmonitorsthenormofwhitenmeasurementvariablesandperformon—linefault
7、identificationbymonitoringeverywhitenvariable,SOtheloadofmonitoringisreduced.AtlastPCAandPPCAarecomparedinmonitoringprocessofchemicalseparation.2.Aimingatthestrongdynamiccharacteristicoftheindustrialprocess,usingEMalgorithm,thedynamicPPCAmodeliSbuilttocopew
8、iththedatamatrixextendbytimeseries.Accordingtothetechnique,staticPPCAcanbeextendedtomonitordynamicmultivariateprocess,andauto—correlationamongprocessvariablesiseffectivelyeliminated.3.Onthemonitoringof