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1、High–SpeedDataAcquisitionSystemBasedonARMLinear-CCDAbstract:Thispaperpresentsahighspeedacquisitionsystemoflinear-CCDbasedonARM,high-speedlinear-CCDandhigh-speedADCareselected.AsthesamplingspeedofA/DisslowerthantheworkingclockfrequencyofARM,CPLDandFIFOa
2、reusedasI/ObetweenA/DandARM.Itmakesthecircuitworksharmonious,simpleandeasycontrolling,andalsoincreasestheefficiencyofARM.Inordertoincreasethecommunicationspeed,theUniversalSerialBus(USB)technologyisadoptedtocommunicatewiththePC.ARMisthekeyprocessorutil
3、izedtocontrolthedatasampling,datacomputeanddatatransfer.Asaresult,thewholesystemworkseffective.Thesystemcanbeappliedtothehighspeeddataacquisitionandoperationsituationsfrommulti-channelanalogsignals.KeyWords:ARM;LinearCCD;Contact-line;Pantograph;Stagger
4、–valueI.IntroductionInelectrificationrailways,inordertoextendthelifeofthepantographonelectriclocomotives,sothatthesliderofpantographwearevenly,thecontact-line(electrifiedrailwaypowerfeedline)instraight-linesegmentsisarrangedaszigzagroute(curvesectionar
5、rangedintheformofpolyline).Thedistancebetweenthecontact-lineofpositioningpointandthepantographcenterlinetrackiscalledoutstagger-value,whichisakeyindicatorofcontact-line.Stagger-valuecannotbeignored,thevaluetoosmallwillaffectthesliderofpantographweareve
6、nlyandthepurposeofextendingusinglife;otherwise,insomecases(suchascaughtinastiffwinds),causealargerangeoflateralmovementoftheroof(andthehigherthespeed,thegreaterpantographswingaround),somepartsofcontact-linewillbeinexcessoftheeffectiveworklengthofpantog
7、raph,sothatthestagger-valueofcontact-linebeyondthestandardrange,leadingtodeteriorationofthecurrentcollection,andevencauseincorrectrunningofthepantographaccident.Pantograph-catenarymalfunctionwillresultininterruptionoftrainoperation,whichimpactonrailtra
8、nsportseriously.Inordertoavoidthesephenomena,thestagger-valueanditschangesshouldbetestedregularly.Therefore,alocomotivecontact-linemonitoringsystemanditsmatingdataacquisitionsystemweredeveloped,whichcalculatetheinstantstagger-valuequick