毕业设计英文文献翻译《基于ARM与线性CCD的高速数据采集系统》

毕业设计中英文翻译学生姓名：学号：学院：专业：指导教师：2011年6月吴轩昂0701054329机电工程学院探测制导与控制技术王利High–SpeedDataAcquisitionSystemBasedonARM&Linear-CCDDongJianjunZhaoXiaojinDept.Four,TheFirstAeronauticalTechnicalCollegeoftheAirForceXinyang464000.China.Abstract:Thispaperpresentsahighspeedacquisitionsystemoflinear-CCDbasedonARM,high-speedlinear-CCDandhigh-speedADCareselected.AsthesamplingspeedofA/DisslowerthantheworkingclockfrequencyofARM,CPLDandFIFOareusedasI/ObetweenA/DandARM.Itmakesthecircuitworksharmonious,simpleandeasycontrolling,andalsoincreasestheefficiencyofARM.Inordertoincreasethecommunicationspeed,theUniversalSerialBus(USB)technologyisadoptedtocommunicatewiththePC.ARMisthekeyprocessorutilizedtocontrolthedatasampling,datacomputeanddatatransfer.Asaresult,thewholesystemworkseffective.Thesystemcanbeappliedtothehighspeeddataacquisitionandoperationsituationsfrommulti-channelanalogsignals.KeyWords:ARM;LinearCCD;Contact-line;Pantograph;Stagger–valueI.IntroductionInelectrificationrailways,inordertoextendthelifeofthepantographonelectriclocomotives,sothatthesliderofpantographwearevenly,thecontact-line(electrifiedrailwaypowerfeedline)instraight-linesegmentsisarrangedaszigzagroute(curvesectionarrangedintheformofpolyline).Thedistancebetweenthecontact-lineofpositioningpointandthepantographcenterlinetrackiscalledoutstagger-value,whichisakeyindicatorofcontact-line.Stagger-valuecannotbeignored,thevaluetoosmallwillaffectthesliderofpantographwearevenlyandthepurposeofextendingusinglife;otherwise,insomecases(suchascaughtinastiffwinds),causealargerangeoflateralmovementoftheroof(andthehigherthespeed,thegreaterpantographswingaround),somepartsofcontact-linewillbeinexcessoftheeffectiveworklengthofpantograph,sothatthestagger-valueofcontact-linebeyondthestandardrange,leadingtodeteriorationofthecurrentcollection,andevencauseincorrectrunningofthepantographaccident.Pantograph-catenarymalfunctionwillresultininterruptionoftrainoperation,whichimpactonrailtransportseriously.Inordertoavoidthesephenomena,thestagger-valueanditschangesshouldbetestedregularly.Therefore,alocomotivecontact-linemonitoringsystemanditsmatingdataacquisitionsystemweredeveloped,whichcalculatetheinstantstagger-valuequickly.II.SystemComponentsSystemhardwarecomponentsareshowninfigure1.Thesystemconsistsofthefollowingcomponents:(1)usingTOSHIBACompany’shigh-speedlineararrayCCDtoachievethedigitizationofcontact-lineimages(CCDoutputthesignalofcorrespondingtimesequenceofposition);(2)usingAtmelCompany’sAT91RM9200processorofARM9seriestorealizedigitalsignalacquisitionandprocessing;(3)usingPDIUSBD12USBinterfacedevicetocompletethedatacommunicationsbetweenmeasurementsystemandthePC.DuetothecharacteristicsofitsimprovedHarvardstructure,specialinstructionsandquicktorealizeavarietyofsignalprocessing,ARMprocessoriswidelyusedinimageprocessing,communications,radar,sonar,precisionmachineryfields,etc.ARMprocessorisadoptedforitsarithmeticspeedandbuswidth.Asthereal-timesignalanalysisandcalculationrequireahighspeedofcomputing,AtmelCompany’sARMchip—AT91RM9200isselected.ThechipisARM920Tbased,high-performance,lowpowerconsumption16/32-bitRISC(reducedinstructionsetcomputer)microcontroller,whichincorporatesarichsetofapplicationperipheralsandprovideasingle-chipsolutionforindustrialcontrolapplicationsthatrequireawiderangeofperipheralsatlowpowerconsumptionandstrictlystableworking.Fig1SystemblockdiagramIII.Real-timeprocessingandtransmissionofCCDdigitalimageInordertoachievereal-timedigitalimagetransmission,severalmajorfactorswhichaffectreal-timetransmissionshouldbenecessarytosolve:First,thespeedoflineararrayCCDdataacquisition;Second,thetransmissionspeedbetweenlineararrayCCDandARMprocessor;thethirdisthedatatransmissionspeedbetweenARMprocessorandcomputer.Thefollowingwillbedescribedindetail.A.LineararrayCCDacquisitionspeedAcquisitionspeedisacriticalperformanceindicatorforimagesensor,TOSHIBACompany’sTCD1209DlineararrayCCDisusedtomeetthetargets.Itsclockpulsefrequencycanoperateashighas20MHz,especiallysuitableforhigh-speedconditionsofsizemeasurementanddynamicanalysis.Fig2LinearCCDTCD1209DanditstimesequencediagramLineararrayCCDTCD1209Danditstimesequencediagramareshowninfigure2.B.TransmissionspeedbetweenCCDandARMprocessorInordertoimprovethespeedofCCDdataacquisitionandreduceconversiontime,adoptinghighspeedA/DconvertercanmakeitexchangedatawithARMprocessorathigh-speed.ADC08200,AnalogCompany'snanosecondconversiondeviceisadopted.It’sasingle-channel,8-bitA/Dconverter,whichoperatesoverawiderangeoftemperature,convertsfast,operatesatconversionratesupto230MSPS,thusachievingentiresignalacquisitionoflineararrayCCD.ADC08200isshowninfigure3.Fig3High-speedA/DconverterADC080200FIFOisusedasadatabuffertoco-ordinatetherateofARMprocessorandADC.Itisatwo-port(inputandoutputport)memoryfortemporarystorageoffirstinfirstoutdata.DuetothetimetowritedatatoFIFOisfarlessthantheA/Dconversiontime,therefore,theacquisitionspeeddependsontheA/Dconversionspeed.Inordertoimprovethespeedoftheentiremeasurementsystem,thetimesequenceofentirecircuitispreciselycontrolledbytheCPLDtomaketheci