外文翻译--基于AT89C2051 的智能型汽车防撞报警器的设计.doc

ANAT89C2051BASEDINTELLIGENTPROXIMITYWARNINGINDICATORFORAUTOMOBILEITINTRODUCESTHEFUNCTIONANDCHARACTERISTICSOFMICROCONTROLLERAT89C2051BASEDONITALOWCOSTHIGHACCURACYMICROMINIATURIZATIONANDDIGITALDISPLAYPROXIMITYWARNINGINDICATORFORAUTOMOBILEISDESIGNEDTHEINDICATORMEASURESTHEDISTANCEANDSPEEDOFTHEAUTOMOBILE,WITHULTRASONICWAVEANDINTEGRATEDHALLUNITANDCONTROLSTHESYSTEMBYTHEREALTIMECONTROLANDDATAPROCESSINGOFTHEMICROCONTROLLERMOREOVERITSCIRCUITRYPRINCIPLEISINTRODUCEDINDETAILASWELLASITSSOFTWAREDESIGNALONGWITHMODERNRHYTHMOFLIFESPEEDINGUP,THEFREQUENCYWHICHTHETRAFFICACCIDENTOCCURREDISINCREASING,FORENHANCESTHESECURITYOFAUTOMOBILEMOVEMENTTHISARTICLEINTRODUCEDONEKINDOFALARMSYSTEMBASEDONMONOLITHICINTEGRATEDCIRCUITCONTROLSTHEAUTOMOBILEGUARDSAGAINSTHITTINGTHISEQUIPMENTTHEMONOLITHICINTEGRATEDCIRCUITREALTIMECONTROLANDTHEDATAPROCESSINGFUNCTION,WITHTHEULTRASONICWAVERANGEFINDERTECHNOLOGY,THESENSORTECHNOLOGYUNIFIES,MAYEXAMINEINTHEAUTOMOBILEMOVEMENTREARAREATHEOBSTACLEANDTHEAUTOMOBILEDISTANCEANDTHEAUTOMOBILEVEHICLESPEED,REVEALSTHEINSTALLMENTDEMONSTRATIONDISTANCETHROUGHTHENUMBER,ANDISAWAYFROMFARANDNEARTHESITUATIONBYTHESOUNDPRODUCTIONELECTRICCIRCUITBASISTOSENDOUTTHEWARNINGSOUNDTHEULTRASONICRANGINGPRINCIPLEIS,AFTERUNCEASINGLYEXAMINESTHEULTRASONICWAVELAUNCHTOMEETTHEECHOWHICHTHEOBSTACLEREFLECTS,THUSDETERMINESTHELAUNCHULTRASONICWAVEANDRECEIVESTHEECHOTHETIMEDIFFERENCETHENEXTRACTSISAWAYFROMSCT/2,CISTHEULTRASONICWAVEWAVEVELOCITY,UNDERTHENORMALTEMPERATURETAKESIS344M/SAFTERSONICSPEEDDETERMINATION,SOLONGASOBTAINSTHEULTRASONICWAVEROUNDTRIPTHETIME,THENOBTAINSTHEDISTANCETHEAUTOMOBILEVEHICLESPEEDSURVEYISINTEGRATESTHESENSORTHROUGHHALLTOREALIZENAMELY,ISLOADEDWITHTHEPERMANENTMAGNETTHETURNTABLEINPUTAXISANDTHEWHEELREVOLUTIONAXISISCONNECTED,WHENTHEWHEELROTATES,THETURNTABLEALONGWITHITROTATION,THISTIME,ONTHETURNTABLEPERMANENTMAGNETCANINTEGRATETHESENSORAFTERHALL,THUSINTEGRATESTHESENSORINHALLTHEINPUTENDTOOBTAINAMAGNETISMSIGNAL,IFTHETURNTABLEDOESNOTSTOPTHEROTATION,HALLINTEGRATESTHESENSORTHENTOBEABLETOOUTPUTTHEROTATIONALSPEEDSIGNALITCANBESAIDTHAT,TOTHEAUTOMOBILEVEHICLESPEEDSURVEYESSENCEINTOTHEROTATIONALSPEEDSIGNALFREQUENCYSURVEYAT89C2051ISALOWPOWERLOSS,THEHIGHPERFORMANCE8CMOSMICROPROCESSOR,ISCOMPATIBLEWITHTHEMCS51SERIESINSTRUCTIONCOLLECTIONANDTHEPIN,HASFOLLOWINGCHARACTERISTIC128BYTESINTERNALRAM,2KBYTESEPROM,FIFTEENI/OLINE,TWOSIXTEENFIXEDTIMECOUNTERS,FIVETWOLEVELOFINTERRUPTSOURCES,ONEENTIREDUPLEXSERIALPORT,INTERNALPRECISELYSIMULATESTHECOMPARATORANDINTERNALSWINGMING,THELOWPOWERLOSSLEAVESUNUSEDANDFALLSTHEELECTRICITYPATTERNTHEWORKINGVOLTAGESCOPE42555V,THEOPERATINGFREQUENCYTAKES12MHZINAT89C2051,TWOSIXTEENFIXEDTIME/COUNTERSREGISTERSIST0ANDT1,MAKEFIXEDTIME/COUNTERS,MAYCOUNTTHEMACHINECYCLE,COUNTSTHEFREQUENCYFORTHEOSCILATIONFREQUENCY1/12；WHENMAKESTHECOUNTER,MAYAPPEARSTOONEXTERIORINPUTPINP34/T0ANDP35/T1FROM1TO0CHANGESWHENINCREASE1,COUNTSTHEFREQUENCYFORTHEOSCILATIONFREQUENCY1/24THISALARMAPPARATUSISMADEUPOFTHECONTROLSYSTEM,THEULTRASONICWAVETRANSMISSIONCIRCUIT,THEACCEPTINGCIRCUIT,MEASUREDTHEFASTELECTRICCIRCUIT,THEALARMCIRCUIT,THELEDDISPLAYCIRCUITETCTHEULTRASONICWAVELAUNCHELECTRICITYROUTECC7555TIMEBASECIRCUITANDTHEULTRASONICWAVELAUNCHPOKESHEADINTOCOMPOSETHEMONOLITHICINTEGRATEDCIRCUITAT89C2051PINCONTROLSTHEP17PINTOCONTROLTHECC7555TIMEBASECIRCUITTOPRODUCETHE40KHZFREQUENCYCODEFORTHEULTRASONICGENERATOR,POKESHEADINTHEULTRASONICWAVELAUNCHOBSTACLEBYTHEULTRASONICWAVEWHICHLAUNCHESHASTHECHARACTERISTICBELOWUSINGTHEULTRASONICRANGINGHIGHSURVEYSENSITIVITY,STRONGPENETRATINGPOWER,QUICKSURVEYSPEED,THEBIGSURVEYANGLEIS,INTHECORRELATIONWIDERANGEOBJECTCARRIESONTHEEXAMINATIONTHESUPERSONICRECEPTIONELECTRICCIRCUITISCOMPOSEDOFPOKESHEADIN,THEAMPLIFIERBANDTHESHAPERCIRCUITTHEULTRASONICWAVEREFLECTSWHICHBYTHEOBSTACLEPOKESHEADINAFTERTHERECEIVE,TOTRANSFORMFORTHEELECTRICITYPULSESIGNAL,AGAINAFTERTHEAMPLIFIER,THESHAPERENLARGEMENTANDTHERESHAPINGSENDSINTHEP32PINOFAT89C2051THEAMPLIFIERSUITABLYSELECTSHASTHEENOUGHGAINANDTHELOWERNOISEWIDEBANDAMPLIFIER,MAINTAINSTHEPULSESIGNALFRONTNOTTOHAVETHEDISTORTIONINPARTICULAR,ENHANCESTHERANGEFINDERTHEPRECISIONMEASUREDTHEFASTELECTRICCIRCUITISCOMPOSEDOFTHESENSOR,THEPULSEAMPLIFIER,THESHAPER,THECC7555TIMEBASESIGNALCIRCUIT,THEGATEHALLINTEGRATESTHESENSORTOTURNTHEWHEELROTATIONALSPEEDSIGNALTHEPULSESIGNALOUTPUT,AFTERTHEENLARGEMENT,THERESHAPINGELECTRICCIRCUITSENDSINTHEGATE,PRODUCESUNITTIMEBASESIGNALCONTROLGATEOPENINGBYTHECC7555TIMEBASECIRCUITSWITHTOSHUT,CONTROLSTHEROTATIONALSPEEDSIGNALINTHEUNITTIMETHROUGHTHEGATE,SENDSINMONOLITHICINTEGRATEDCIRCUITTHEP35PINOFAT89C2051,CONTROLLEDTHET1COUNTERTOCOUNT,HASREALIZEDINUNITTIMECOUNTINGTHEALARMCIRCUITISCOMPOSEDOFTHECC7555ELECTRICCIRCUITSANDTHESPEAKERTHEP16PINOFAT89C2051CONTROLSTHECC7555ELECTRICCIRCUITBASISMEASUREMENTRESULT,PRODUCESTHECERTAINFREQUENCYSIGNALACTUATIONSPEAKERTOSENDOUTREPORTSTOTHEPOLICETHESOUNDSENDSOUTWHENTHESPEAKERREPORTSTOTHEPOLICETHESOUND,TIMEBASECIRCUITCC7555ISINTEMPORARILYTHESTABLESTATE,THISTIMEPOWERSOURCETOELECTRICCAPACITYCHARGE,THUSCAUSESCC7555TOENDTEMPORARILYTHESTABLESTATETOREPLYTHESTEADYSTATE,OUTPUTSTHELOWLEVEL,CAUSESTHESPEAKERTOSTO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