外文翻译--基于AT89C2051 的智能型汽车防撞报警器的设计.doc

AnAT89C2051BasedIntelligentProximityWarningIndicatorforAutomobileItintroducesthefunctionandcharacteristicsofmicrocontrollerAT89C2051Basedonit.Alowcosthigh-accuracymicrominiaturizationanddigitaldisplayproximitywarningindicatorforautomobileisdesigned.Theindicatormeasuresthedistanceandspeedoftheautomobile,withultrasonicwaveandintegratedHallunitandcontrolsthesystembythereal-timecontrolandData-processingofthemicrocontrollerMoreover.itscircuitryprincipleisintroducedindetailaswellasitssoftwaredesign.Alongwithmodernrhythmoflifespeedingup,thefrequencywhichthetrafficaccidentoccurredisincreasing,forenhancesthesecurityofautomobilemovement.Thisarticleintroducedonekindofalarmsystembasedonmonolithicintegratedcircuitcontrolstheautomobileguardsagainsthitting.Thisequipmentthemonolithicintegratedcircuitreal-timecontrolandthedataprocessingfunction,withtheultrasonicwaverangefindertechnology,thesensortechnologyunifies,mayexamineintheautomobilemovementrearareatheobstacleandtheautomobiledistanceandtheautomobilevehiclespeed,revealstheinstallmentdemonstrationdistancethroughthenumber,andisawayfromfarandnearthesituationbythesoundproductionelectriccircuitbasistosendoutthewarningsound.Theultrasonicrangingprincipleis,afterunceasinglyexaminestheultrasonicwavelaunchtomeettheechowhichtheobstaclereflects,thusdeterminesthelaunchultrasonicwaveandreceivestheechothetimedifference.ThenextractsisawayfromS=CT/2,Cistheultrasonicwavewavevelocity,underthenormaltemperaturetakesis344m/s.Aftersonicspeeddetermination,solongasobtainstheultrasonicwaveround-tripthetime,thenobtainsthedistance.TheautomobilevehiclespeedsurveyisintegratesthesensorthroughHalltorealize.Namely,isloadedwiththepermanentmagnettheturntableinputaxisandthewheelrevolutionaxisisconnected,whenthewheelrotates,theturntablealongwithitrotation,thistime,ontheturntablepermanentmagnetcanintegratethesensorafterHall,thusintegratesthesensorinHalltheinputendtoobtainamagnetismsignal,iftheturntabledoesnotstoptherotation,Hallintegratesthesensorthentobeabletooutputtherotationalspeedsignal.Itcanbesaidthat,totheautomobilevehiclespeedsurveyessenceintotherotationalspeedsignalfrequencysurvey.AT89C2051isalowpowerloss,thehighperformance8CMOSmicroprocessor,iscompatiblewiththeMCS-51seriesinstructioncollectionandthepin,hasfollowingcharacteristic:128bytesinternalRAM,2KbytesEPROM,fifteenI/Oline,twosixteen-fixedtimecounters,fivetwo-levelofinterruptsources,oneentireduplexserialport,internalpreciselysimulatesthecomparatorandinternalswingming,thelowpowerlossleavesunusedandfallstheelectricitypattern.Theworkingvoltagescope4.255.5V,theoperatingfrequencytakes12MHz.InAT89C2051,twosixteen-fixedtime/countersregistersisT0andT1,makefixedtime/counters,maycountthemachinecycle,countsthefrequencyfortheoscilationfrequency1/12；Whenmakesthecounter,mayappearstoonexteriorinputpinP3.4/T0andP3.5/T1from1to0changeswhenincrease1,countsthefrequencyfortheoscilationfrequency1/24.Thisalarmapparatusismadeupofthecontrolsystem,theultrasonicwavetransmissioncircuit,theacceptingcircuit,measuredthefastelectriccircuit,thealarmcircuit,theLEDdisplaycircuitetc.TheultrasonicwavelaunchelectricityrouteCC7555timebasecircuitandtheultrasonicwavelaunchpokesheadintocompose.ThemonolithicintegratedcircuitAT89C2051pincontrolstheP1.7pintocontroltheCC7555timebasecircuittoproducethe40kHzfrequencycodefortheultrasonicgenerator,pokesheadintheultrasonicwaveLaunchobstaclebytheultrasonicwavewhichlaunches.Hasthecharacteristicbelowusingtheultrasonicranging:highsurveysensitivity,strongpenetratingpower,quicksurveyspeed,thebigsurveyangleis,inthecorrelationwiderangeobjectcarriesontheexamination.Thesupersonicreceptionelectriccircuitiscomposedofpokesheadin,theamplifierbandtheshapercircuit.Theultrasonicwavereflectswhichbytheobstaclepokesheadinafterthereceive,totransformfortheelectricitypulsesignal,againaftertheamplifier,theshaperenlargementandthereshapingsendsintheP3.2pin.ofAT89C2051.Theamplifiersuitablyselectshastheenoughgainandthelowernoisewidebandamplifier,maintainsthepulsesignalfrontnottohavethedistortioninparticular,enhancestherangefindertheprecision.Measuredthefastelectriccircuitiscomposedofthesensor,thepulseamplifier,theshaper,theCC7555timebasesignalcircuit,thegate.Hallintegratesthesensortoturnthewheelrotationalspeedsignalthepulsesignaloutput,aftertheenlargement,thereshapingelectriccircuitsendsinthegate,producesunittimebasesignalcontrolgateopeningbytheCC7555timebasecircuitswithtoshut,controlstherotationalspeedsignalintheunittimethroughthegate,sendsinmonolithicintegratedcircuittheP3.5pinofAT89C2051,controlledtheT1countertocount,hasrealizedinunittimecounting.ThealarmcircuitiscomposedoftheCC7555electriccircuitsandthespeaker.TheP1.6pinofAT89C2051controlstheCC7555electriccircuitbasismeasurementresult,producesthecertainfrequencysignalactuationspeakertosendoutreportstothepolicethesound.Sendsoutwhenthespeakerreportstothepolicethesound,timebasecircuitCC7555isintemporarilythestablestate,thistimepowersourcetoelectriccapacitycharge,thuscausesCC7555toendtemporarilythestablestatetoreplythesteadystate,outputsthelowlevel,causesthespeakertostopsendingoutreportstothepolicethesound,producesnewlyuntilthenextrangefinderconclusionreportstothepolicethesound.TheLEDdisplaycircuitiscomposedofthedigitaltubeandtheactuationelectriccircuit.Withtwodigitaltubesdemonstrationdistance,thedigitaltubeusesthestaticstatetodemonstratethat,bythechipMCS14495actuationsdemonstrations,P1.4,P1.5separatelysavesthesignalastheactuationchipMCS14495locks,usesinBCDwhichcontrolsproduces(BinarCodeDecimal),thebinarycodeexpressiontensdigitisdemonstratesthetopdigitorthelowposition.TheAT89C2051mainlycompletestheproceduretheexecution,dataprocessingandtoexteriorelectriccircuitreal-timecontrol.InternaltimerT0workinfixedtimeway,whenultrasonicwavelaunchstartstocount,afterpinP3.2receivestheecho,stopscounting,T0timesnamelyfortheultrasonicwaveround-triptransmissiontime,themonolithicintegratedcircuitcarriesonprocessingtothisdata,thendeterminesthedistance.TheinternaltimerT1workiscountingtheway,countsbyP3.5pininputpulsesignalcontrolT1,countsthevaluebyT1todeterminetheautomobiletherotationalspeed.Themonolithicintegratedcircuitbasismeasuredisawayfromandthevehiclespeedcarriesonthecomparison,judgeswhetheractuatesthealarmcircuittoreporttothepolice,likehypothesis:Whenthevehiclespeedissmallerorequalto30km/s,thesafedistanceshouldbebiggerthanisequalto1m；Whenthevehiclespeedissmallerorequalto80km/s,thesafedistanceshouldbebiggerthanisequalto2m；Whenthevehiclespeedisbiggerthan80km/s,thesafedistanceshouldbebiggerthanisequalto5m.Thisinstallmentcontrolsoftwaremustcompletethesysteminitialization,thecontroltriggerpulsesignallaunchandthereceive,accordingtofixedtimethecount-downobstacledistance,accordingtocountsthefrequencycomputationautomobilevehiclespeed,judgesmeasuredisawayfromwhetherinthemarginforsafetywhichthevehiclespeedcorresponds,andaccordingtocalculateshastheBCDcodeandthecorrespondingfrequencypulsesignalwiththejudgementresult,actuatesthedisplaycircuitandthesoundproductionelectriccircuit基于AT89C2051的智能型汽车防撞报警器的设计本文介绍了AT89C2051单片机的性能及特点，及以其为核心的一种低成本、高精度、微型化、数字显示的汽车防撞报警器。该防撞报警器利用超声波及集成霍尔元件实现对汽车的测距和测速，利用单片机的实时控制和数据处理功能，完成系统的控制。文章给出了报警器的硬件电路原理及软件设计。随着现代生活节奏的加快，交通事故发生的频率也在增加，为提高汽车运行的安全性，本文介绍一种单片机控制的汽车防撞报警系统。该装置将单片机的实时控制及数据处理功能，与超声波的测距技术、传感器技术相结合，可检测汽车运行中后方障碍物与汽车的距离及汽车车速，通过数显装置显示距离，并由发声电路根据距离远近情况发出警告声。超声波测距的原理是，通过不断检测超声波发射后遇到障碍物所反射的回波，从而测出发射超声波和接收到回波的时间差，然后求出距离S=CT/2，其中，C为超声波波速，常温下取为344m/s。声速确定后，只要测得超声波往返的时间，即可求得距离。汽车车速的测量是通过霍尔集成传感器来实现的。即，装有永久磁铁的转盘的输入轴与车轮的转轴相连，当车轮转动时，转盘随之转动，此时，转盘上的永久磁铁会经过霍尔集成传感器，从而在霍尔集成传感器的输入端得到一个磁信号，如果转盘不停转动，霍尔集成传感器便会