汽车倒车测距仪毕业设计外文翻译Word下载.docx

汽车倒车测距仪毕业设计外文翻译Word下载.docx

《汽车倒车测距仪毕业设计外文翻译Word下载.docx》由会员分享，可在线阅读，更多相关《汽车倒车测距仪毕业设计外文翻译Word下载.docx（8页珍藏版）》请在冰豆网上搜索。

A.BACKGROUNDOFTHEINVENTION

Thisinventionrelatestoapparatusforthemeasurementofdistanceandmoreparticularlytosuchapparatuswhichtransmitsultrasonicwavesbetweentwopoints.

Precisionmachinetoolsmustbecalibrated.Inthepastthishasbeenaccomplishedutilizingmechanicaldevicessuchascalipersmicrometersandthelike.Howevertheuseofsuchdevicesdoesnotreadilylenditselftoautomationtechniques.Itisknownthatthedistancebetweentwopointscanbedeterminedbymeasuringthepropagationtimeofawavetravellingbetweenthosetwopoints.Onesuchtypeofwaveisanultrasonicoracousticwave.Whenanultrasonicwavetravelsbetweentwopointsthedistancebetweenthetwopointscanbemeasuredbymultiplyingthetransittimeofthewavebythewavevelocityinthemediumseparatingthetwopoints.Itisthereforeanobjectofthepresentinventiontoprovideapparatusutilizingultrasonicwavestoaccuratelymeasurethedistancebetweentwopoints.

Whenthemediumbetweenthetwopointswhosespacingisbeingmeasuredisairthesoundvelocityisdependentuponthetemperatureandhumidityoftheair.Itisthereforeafurtherobjectofthepresentinventiontoprovideapparatusofthetypedescribedwhichisindependentoftemperatureandhumidityvariations.

B.SUMMARYOFTHEINVENTION

Theforegoingandadditionalobjectsareattainedinaccordancewiththeprinciplesofthisinventionbyprovidingdistancemeasuringapparatuswhichincludesareferenceunitandameasuringunit.Thereferenceandmeasuringunitsarethesameandeachincludesanelectroacoustictransmitterandanelectroacousticreceiver.Thespacingbetweenthetransmitterandthereceiverofthereferenceunitisafixedreferencedistancewhereasthespacingbetweenthetransmitterandreceiverofthemeasuringunitisthedistancetobemeasured.Ineachoftheunitsthetransmitterandreceiverarecoupledbyafeedbackloopwhichcausesthetransmittertogenerateanacousticpulsewhichisreceivedbythereceiverandconvertedintoanelectricalpulsewhichisthenfedbacktothetransmittersothatarepetitiveseriesofpulsesresults.Therepetitionrateofthepulsesisinverselyrelatedtothedistancebetweenthetransmitterandthereceiver.Ineachoftheunitsthepulsesareprovidedtoacounter.Sincethereferencedistanceisknowntheratioofthecounteroutputsisutilizedtodeterminethedesireddistancetobemeasured.Sincebothcountsareidenticallyinfluencedbytemperatureandhumidityvariationsbytakingtheratioofthecountstheresultantmeasurementbecomesinsensitivetosuchvariations.

C.DETAILEDDESCRIPTION

A.principleofultrasonicdistancemeasurement

1.theprincipleofpiezoelectricultrasonicgenerator

Piezoelectricultrasonicgeneratoristheuseofpiezoelectriccrystalresonatorstowork.UltrasonicgeneratortheinternalstructureasshowninFigure1ithastwopiezoelectricchipandaresonanceplate.Whenitstwopluspulsesignalthefrequencyequaltotheintrinsicpiezoelectricoscillationfrequencychipthechipwillhappenpiezoelectricresonanceandpromotethedevelopmentofplatevibrationresonanceultrasoundisgenerated.Converselyifthetwoarenotinter-electrodevoltagewhentheboardreceivedultrasonicresonanceitwillbeforvibrationsuppressionofpiezoelectricchipthemechanicalenergyisconvertedtoelectricalsignalsthenitbecomestheultrasonicreceiver.

2.theprincipleofultrasonicdistancemeasurement

Ultrasonictransmitterinadirectiontolaunchultrasoundinthemomenttolaunchthebeginningoftimeatthesametimethespreadofultrasoundintheairobstaclesonhiswaytoreturnimmediatelytheultrasonicreflectedwavereceivedbythereceiverimmediatelystoptheclock.Ultrasoundintheairasthepropagationvelocityof340m/saccordingtothetimerrecordsthetimetwecancalculatethedistancebetweenthelaunchdistancebarriersthatis:

s=340t/2

B.UltrasonicRangingSystemfortheSecondCircuitDesign

Systemischaracterizedbysingle-chipmicrocomputertocontroltheuseofultrasonictransmitterandultrasonicreceiversincethelaunchfromtimetotimesingle-chipselectionof8751economic-to-useandthechiphas4KofROMtofacilitateprogramming.CircuitschematicdiagramshowninFigure2.DrawonlythefrontrangeofthecircuitwiringdiagramleftandrightinfrontofRangingRangingcircuitsandthesamecircuititisomitted.

1.40kHzultrasonicpulsegeneratedwiththelaunch.

RangingsystemusingtheultrasonicsensorofpiezoelectricceramicsensorsUCM40itsoperatingvoltageofthepulsesignalis40kHzwhichbythesingle-chipimplementationofthefollowingprocedurestogenerate.puzel:

mov14h12hultrasonicfiringcontinued200ms

here:

cplp1.0output40kHzsquarewave

nop;

djnz14h,here;

ret

Ranginginfrontofsingle-chipterminationcircuitP1.0inputportsinglechipimplementationoftheaboveproceduretheP1.0portina40kHzpulseoutputsignalafteramplificationtransistorTthedrivetolaunchthefirstultrasonicUCM40Tissued40kHzultrasonicpulseandthecontinuedlaunchof200ms.RangingtherightandtheleftsideofthecircuitrespectivelytheninputportP1.1andP1.2theworkingprincipleandcircuitinfrontofthesamelocation.

2.receptionandprocessingofultrasonic

UsedtoreceivethefirstlaunchofthefirstpairUCM40Rtheultrasonicpulsemodulationsignalintoanalternatingvoltagetheop-ampamplificationIC1AandafterpolarizationIC1BtoIC2.IC2islockedloopwithaudiodecoderchipLM567internalvoltage-controlledoscillatorcenterfrequencyoff01/1.1R8C3capacitorC4determinetheirtargetbandwidth.R8-conditioninginthelaunchofthecarrierfrequencyontheLM567inputsignalisgreaterthan25mVtheoutputfromthehighjump8feetintoalow-levelasinterruptrequestsignalstothesingle-chipprocessing.

Ranginginfrontofsingle-chipterminationcircuitoutputportINT0interruptthehighestpriorityrightorleftlocationoftheoutputcircuitwithoutputgateIC3AaccessINT1portsingle-chipwhilesingle-chipP1.3andP1.4receivedinputIC3Ainterruptedbytheprocesstoidentifythesourceofinquirytodealwithinterruptprioritylevelforthefirstleftrightafter.Partofthesourcecodeisasfollows:

receive1:

pushpsw

pushacc

clrex1;

relatedexternalinterrupt1

jnbp1.1right;

P1.1pinto0,rangingfromrighttointerruptserviceroutinecircuit

jnbp1.2leftP1.2pinto0,totheleftrangingcircuit

interruptserviceroutine

return:

SETBEX1;

openexternalinterrupt1

pop?

acc

psw

reti

right:

...?

;

rightlocationentrancecircuitinterruptserviceroutine

?

AjmpReturn

left:

...leftRangingentrancecircuitinterruptserviceroutine

Ajmp?

Return

3.thecalculationofultrasonicpropagationtime

Whenyoustartfiringatthesametimestartthesingle-chipcircuitrywithinthetimerT0theuseoftimercountingfunctionrecordsthetimeandthelaunchofultrasonicreflectedwavereceivedtime.WhenyoureceivetheultrasonicreflectedwavethereceivercircuitoutputsanegativejumpintheendofINT0orINT1interruptrequestgeneratesasignalsingle-chipmicrocomputerinresponsetoexternalinterruptrequesttheimplementationoftheexternalinterruptservicesubroutinereadthetimedifferencecalculatingthedistance.Someofitssourcecodeisasfollows:

RECEIVE0:

PUSHPSW

PUSHACC

CLREX0;

relatedexternalinterrupt0

MOVR7,TH0;

readthetimevalue

MOVR6TL0?

CLRC

MOVA,R6

SUBBA,#0BBH;

calculatethetimedifference

MOV31H,A;

storageresults

MOVA,R7

SUBBA,#3CH

MOV30H,A?

SETBEX0;

openexternalinterrupt0

POPACC?

POPPSW

RETI

D.Fourththeultrasonicrangingsystemsoftwaredesign

SoftwareisdividedintotwopartsthemainprogramandinterruptserviceroutineshowninFigure3（a）（b）（c）below.Completionoftheworkofthemainprogramisinitializedeachsequenceofultrasonictransmittingandreceivingcontrol.

Interruptserviceroutinesfromtimetotimetocompletethreeoftherotationdirectionofultrasoniclaunchthemainexternalinterruptservicesubroutinetoreadthevalueofcompletiontimedistancecalculationtheresultsoftheoutputandsoon.

E.CONCLUSIONS

Requiredmeasuringrangeof30cm200cmobjectsinsidetheplanetodoanumberofmeasurementsfoundthatthemaximumerroris0.5cmandgoodreproducibility.Single-chipdesigncanbeseenontheultrasonicrangingsystemhasahardwarestructureissimplereliablesmallfeaturessuchasmeasurementerror.Thereforeitcanbeusednotonlyformobilerobotcanbeusedinotherdetectionsystems.

Thoughts:

AsforwhythereceiverdonothavethetransistoramplifiercircuitbecausethemagnificationwellCX20106integratedamplifierbutalsowithautomaticgaincontrollevelmagnificationto76dBthecenterfrequencyis38kto40kisexactlyresonantultrasonicsensorsfrequency. 

翻译：

超声波测距仪

文件类型和数目：

美国专利5442592

摘要：

提出了一种可以抵消温度的影响和湿度的变化的新型超声波测距仪，包括测量单元和参考标准。

在每一个单位，重复的产生一系列脉冲，每一个重复直接关系到发射机和接收机之间的距离。

脉冲串提供给各级的计数器，然后利用计数器所测得的数据进行距离的测量。

出版日期：

1995年8月15日

主审查员：

罗保.伊恩j.

一、背景发明

本发明涉及到仪器的测量距离，更特别的是，这种仪器传送超声波于两点之间。

精密机器必须校准。

在过去