汽车电子超声测距系统中英文外文翻译.docx

汽车电子超声测距系统中英文外文翻译.docx

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汽车电子超声测距系统中英文外文翻译

中英文对照资料外文翻译文献

Ultrasonicrangingsystemdesign

ABSTRACT:

Ultrasonicrangingtechnologyhaswideusingworthinmanyfields,suchastheindustriallocale,vehiclenavigationandsonarengineering.Nowithasbeenusedinlevelmeasurement,self-guidedautonomousvehicles,fieldworkrobotsautomotivenavigation,airandunderwatertargetdetection,identification,locationandsoon.Sothereisanimportantpracticingmeaningtolearntherangingtheoryandwaysdeeply.Toimprovetheprecisionoftheultrasonicrangingsysteminhand,satisfytherequestoftheengineeringpersonnelfortherangingprecision,theboundandtheusage,aportableultrasonicrangingsystembasedonthesinglechipprocessorwasdeveloped.

Keywords:

Ultrasound,RangingSystem,SingleChipProcessor

1.Introductive

Withthedevelopmentofscienceandtechnology,theimprovementofpeople’sstandardofliving,speedingupthedevelopmentandconstructionofthecity.Urbandrainagesystemhavegreatlydevelopedtheirsituationisconstructionimproving.However,duetohistoricalreasonsmanyunpredictablefactorsinthesynthesisofhertime,thecitydrainagesystem.Inparticulardrainagesystemoftenlagsbehindurbanconstruction.Therefore,thereareoftengoodbuildingexcavationhasbeenbuildingfacilitiestoupgradethedrainagesystemphenomenon.Itbroughttothecitysewage,anditiscleartothecitysewageanddrainageculvertinthesewagetreatmentsystem.Comfortisveryimportanttopeople’slives.MobilerobotsdesignedtoclearthedrainageculvertandtheautomaticcontrolsystemFreesewageculvertclearguaranteerobots,therobotisdesignedtocleartheculvertsewagetothecore.Controlsystemisthecorecomponentofthedevelopmentofultrasonicrangefinder.Therefore,itisveryimportanttodesignagoodultrasonicrangefinder.

2.Aprincipleofultrasonicdistancemeasurement

TheapplicationofAT89C51:

SCMisamajorpieceofcomputercomponentsareintegratedintothechipmicro-computer.Itisamulti-interfaceandcountingonthemicro-controllerintegration,andintelligenceproductsarewidelyusedinindustrialautomation.andMCS-51microcontrollerisatypicalandrepresentative.

Microcontrollersareusedinamultitudeofcommercialapplicationssuchasmodems,motor-controlsystems,airconditionercontrolsystems,automotiveengineandamongothers.Thehighprocessingspeedandenhancedperipheralsetofthesemicrocontrollersmakethemsuitableforsuchhigh-speedevent-basedapplications.However,thesecriticalapplicationdomainsalsorequirethatthesemicrocontrollersarehighlyreliable.Thehighreliabilityandlowmarketriskscanbeensuredbyarobusttestingprocessandapropertoolsenvironmentforthevalidationofthesemicrocontrollersbothatthecomponentandatthesystemlevel.IntelPlaformEngineeringdepartmentdevelopedanobject-orientedmulti-threadedtestenvironmentforthevalidationofitsAT89C51automotivemicrocontrollers.ThegoalsofthisenvironmentwasnotonlytoprovidearobusttestingenvironmentfortheAT89C51automotivemicrocontrollers,buttodevelopanenvironmentwhichcanbeeasilyextendedandreusedforthevalidationofseveralotherfuturemicrocontrollers.TheenvironmentwasdevelopedinconjunctionwithMicrosoftFoundationClasses（AT89C51）.

1.1Features

*CompatiblewithMCS-51Products

*2KbytesofReprogrammableFlashMemory

Endurance:

1,000Write/EraseCycles

*2.7Vto6VOperatingRange

*FullyStaticoperation:

0Hzto24MHz

*Two-levelprogrammemorylock

*128x8-bitinternalRAM

*15programmableI/Olines

*Two16-bittimer/counters

*Sixinterruptsources

*ProgrammableserialUARTchannel

*DirectLEDdriveoutput

*On-chipanalogcomparator

*Lowpoweridleandpowerdownmodes

1.2Description

TheAT89C2051isalow-voltage,high-performanceCMOS8-bitmicrocomputerwith2Kbytesofflashprogrammableanderasablereadonlymemory（PEROM）.ThedeviceismanufacturedusingAtmel’shighdensitynonvolatilememorytechnologyandiscompatiblewiththeindustrystandardMCS-51instructionsetandpinout.Bycombiningaversatile8-bitCPUwithflashonamonolithicchip,theAtmelAT89C2051isapowerfulmicrocomputerwhichprovidesahighlyflexibleandcosteffectivesolutiontomanyembeddedcontrolapplications.

TheAT89C2051providesthefollowingstandardfeatures:

2Kbytesofflash,128bytesofRAM,15I/Olines,two16-bittimer/counters,afivevectortwo-levelinterruptarchitecture,afullduplexserialport,aprecisionanalogcomparator,on-chiposcillatorandclockcircuitry.Inaddition,theAT89C2051isdesignedwithstaticlogicforoperationdowntozerofrequencyandsupportstwosoftwareselectablepowersavingmodes.TheidlemodestopstheCPUwhileallowingtheRAM,timer/counters,serialportandinterruptsystemtocontinuefunctioning.ThepowerdownmodesavestheRAMcontentsbutfreezertheoscillatordisablingallotherchipfunctionsuntilthenexthardwarereset.

1.3PinConfiguration

1.4PinDescription

VCCSupplyvoltage.

GNDGround.

Prot1

Prot1isan8-bitbidirectionalI/Oport.PortpinsP1.2toP1.7provideinternalpullups.P1.0andP1.1requireexternalpullups.P1.0andP1.1alsoserveasthepositiveinput（AIN0）andthenegativeinput（AIN1）,respectively,oftheon-chipprecisionanalogcomparator.Theport1outputbufferscansink20mAandcandriveLEDdisplaysdirectly.When1sarewrittentoport1pins,theycanbeusedasinputs.WhenpinsP1.2toP1.7areusedasinputandareexternallypulledlow,theywillsourcecurrent（IIL）becauseoftheinternalpullups.

Port3

Port3pinsP3.0toP3.5,P3.7aresevenbidirectionalI/Opinswithinternalpullups.P3.6ishard-wiredasaninputtotheoutputoftheon-chipcomparatorandisnotaccessibleasageneralpurposeI/Opin.Theport3outputbufferscansink20mA.When1sarewrittentoport3pinstheyarepulledhighbytheinternalpullupsandcanbeusedasinputs.Asinputs,port3pinsthatareexternallybeingpulledlowwillsourcecurrent（IIL）becauseofthepullups.

Port3alsoservesthefunctionsofvariousspecialfeaturesoftheAT89C2051aslistedbelow.

1.5ProgrammingtheFlash

TheAT89C2051isshippedwiththe2Kbytesofon-chipPEROMcodememoryarrayintheerasedstate（i.e.,contents=FFH）andreadytobeprogrammed.Thecodememoryarrayisprogrammedonebyteatatime.Oncethearrayisprogrammed,tore-programanynon-blankbyte,theentirememoryarrayneedstobeerasedelectrically.

Internaladdresscounter:

theAT89C2051containsaninternalPEROMaddresscounterwhichisalwaysresetto000HontherisingedgeofRSTandisadvancedapplyingapositivegoingpulsetopinXTAL1.

Programmingalgorithm:

toprogramtheAT89C2051,thefollowingsequenceisrecommended.

1.power-upsequence:

ApplypowerbetweenVCCandGNDpinsSetRSTandXTAL1toGND

Withallotherpinsfloating,waitforgreaterthan10milliseconds

2.SetpinRSTto‘H’setpinP3.2to‘H’

3.Applytheappropriatecombinationof‘H’or‘L’logictopinsP3.3,P3.4,P3.5,P3.7toselectoneoftheprogrammingoperationsshowninthePEROMprogrammingmodestable.

ToprogramandVerifytheArray:

4.Applydataforcodebyteatlocation000HtoP1.0toP1.7.5.RaiseRSTto12Vtoenableprogramming.

5.PulseP3.2oncetoprogramabyteinthePEROMarrayorthelockbits.Thebyte-writecycleisself-timedandtypicallytakes1.2ms.

6.Toverifytheprogrammeddata,lowerRSTfrom12Vtologic‘H’levelandsetpinsP3.3toP3.7totheappropriatelevels.OutputdatacanbereadattheportP1pins.

7.Toprogramabyteatthenextaddresslocation,pulseXTAL1pinoncetoadvancetheinternaladdresscounter.ApplynewdatatotheportP1pins.

8.Repeatsteps5through8,changingdataandadvancingtheaddresscounterfortheentire2Kbytesarrayoruntiltheendoftheobjectfileisreached.

9.Power-offsequence:

setXTAL1to‘L’setRSTto‘L’

FloatallotherI/OpinsTurnVCCpoweroff

2.1Theprincipleofpiezoelectricultrasonicgenerator

Piezoelectricultrasonicgeneratoristheuseofpiezoelectriccrystalresonatorstowork.Ultrasonicgenerator,theinternalstructureasshown,ithastwopiezoelectricchipandaresonanceplate.Whenit’stwopluspulsesignal,thefrequencyequaltotheintrinsicpiezoelectricoscillationfrequencychip,thechipwillhappenpiezoelectricresonance,andpromotethedevelopmentofplatevibrationresonance,ultrasoundisgenerated.Conversely,itwillbeforvibrationsuppressionofpiezoelectricchip,themechanicalenergyisconvertedtoelectricalsignals,thenitbecomestheultrasonicreceiver.

Thetraditionalwaytodeterminethemomentoftheecho’sarrivalisbasedonthresholdingthereceivedsignalwithafixedreference.Thethresholdischosenwellabovethenoiselevel,whereasthemomentofarrivalofanechoisdefinedasthefirstmomenttheechosignalsurpassesthatthreshold.Theintensityofanechoreflectingfromanobjectstronglydependsontheobject’snature,sizeanddistancefromthesensor.Further,thetimeintervalfromtheecho’sstartingpointtothemomentwhenitsurpassesthethresholdchangeswiththeintensityoftheecho.Asaconsequence,aconsiderableerrormayoccureventwoechoeswithdifferentintensitiesarrivingexactlyatthesametimewillsurpassthethresholdatdifferentmoments.Thestrongeronewillsurpassthethresholdearlierthantheweaker,soitwillbeconsideredasbelongingtoanearerobject.

2.2Theprincipleofultrasonicdistancemeasurement

Ultrasonictransmitterinadirectiontolaunchultrasound,inthemomenttolaunchthebeginningoftimeatthesametime,thespreadofult