文献翻译——超声测距系统设计

第1页外文文献资料UltrasonicrangingsystemdesignABSTRACT：Ultrasonicrangingtechnologyhaswideusingworthinmanyfields，suchastheindustriallocale，vehiclenavigationandsonarengineeringNowithasbeenusedinlevelmeasurement，self-guidedautonomousvehicles,fieldworkrobotsautomotivenavigation，airandunderwatertargetdetection，identification，locationandsoonSothereisanimportantpracticingmeaningtolearntherangingtheoryandwaysdeeply.Toimprovetheprecisionoftheultrasonicrangingsysteminhand，satisfytherequestoftheengineeringpersonnelfortherangingprecision，theboundandtheusage，aportableultrasonicrangingsystembasedonthesinglechipprocessorwasdeveloped1.IntroductiveWiththedevelopmentofscienceandtechnology,theimprovementofpeoplesstandardofliving,speedingupthedevelopmentandconstructionofthecity.urbandrainagesystemhavegreatlydevelopedtheirsituationisconstantlyimproving.However,duetohistoricalreasonsmanyunpredictablefactorsinthesynthesisofhertime,thecitydrainagesystem.Inparticulardrainagesystemoftenlagsbehindurbanconstruction.Therefore,thereareoftengoodbuildingexcavationhasbeenbuildingfacilitiestoupgradethedrainagesystemphenomenon.Itbroughttothecitysewage,fortisveryimportanttopeopleslives.MobilerobotsdesignedtoclearthedrainageculvertandtheautomaticcontrolsystemFreesewageculvertclearguaranteerobot,therobotisdesignedtocleartheculvertsewagetothecore.ControlSystemisthecorecomponentofthedevelopmentofultrasonicrangefinder.Therefore,itisveryimportanttodesignagoodultrasonicrangefinder.第2页Precisionmachinetoolsmustbecalibrated.Inthepast,thishasbeenaccomplishedutilizingmechanicaldevicessuchascalipers,micrometers,andthelike.However,theuseofsuchdevicesdoesnotreadilylenditselftoautomationtechniques.Itisknownthatthedistancebetweentwopointscanbedeterminedbymeasuringthepropagationtimeofawavetravellingbetweenthosetwopoints.Onesuchtypeofwaveisanultrasonic,oracoustic,wave.Whenanultrasonicwavetravelsbetweentwopoints,thedistancebetweenthetwopointscanbemeasuredbymultiplyingthetransittimeofthewavebythewavevelocityinthemediumseparatingthetwopoints.Itisthereforeanobjectofthepresentinventiontoprovideapparatusutilizingultrasonicwavestoaccuratelymeasurethedistancebetweentwopoints.Whenthemediumbetweenthetwopointswhosespacingisbeingmeasuredisair,thesoundvelocityisdependentuponthetemperatureandhumidityoftheair.Itisthereforeafurtherobjectofthe,presentinventiontoprovideapparatusofthetypedescribedwhichisindependentoftemperatureandhumidityvariations.Distancehasbeenoneofthebasicfactorsinmanufacturingandcontrolfields,andultrasonicdistancesensorshavebeenwidelyusedasalow-costmeasuringtool.However,thepropagationofultrasonicwavesisgreatlyaffectedbyenvironmentalfactorssuchastemperature,humidityandatmosphericpressure.Inordertosolvetheproblemofinaccuratemeasurement,whichissignificantwithinindustry,thispaperpresentsanovelultrasonicdistancesensormodelusingnetworkederrorcorrection(NEC)trainedonexperimentaldata.Thisismoreaccuratethanotherexistingapproachesbecauseitusesinformationfromindirectassociationwithneighboringsensors,whichhasnotbeenconsideredbefore.TheNECtechnique,focusingonoptimizationoftherelationshipofthetopologicalstructure.ofsensorarrays,isimplementedforthecompensationoferroneousmeasurementscausedbytheenvironment.Weapplythemaximumlikelihoodmethodtodeterminetheoptimalfusiondatasetanduseaneighbordiscoveryalgorithmtoidentifyneighbornodesatthetopspeed.Furthermore,weadopttheNECoptimizationalgorithm,whichtakesfulladvantageofthecorrelationcoefficientsforneighborsensors.Theexperimentalresultsdemonstratethattheranging第3页errorsoftheNECsystemarewithin2.20%;furthermore,themeanabsolutepercentageerrorisreducedto0.01%afterthreeiterationsofthismethod,whichmeansthattheproposedmethodperformsextremelywell.Theoptimizedmethodofdistancemeasurementwepropose,withthecapabilityofNEC,wouldbringasignificantadvantageforintelligentindustrialautomation2.Aprincipleofultrasonicdistancemeasurement2.1.TheprincipleofpiezoelectricultrasonicgeneratorPiezoelectricultrasonicgeneratoristheuseofpiezoelectriccrystalresonatorstowork.Ultrasonicgenerator,theinternalstructureasshown,ithastwopiezoelectricchipandaresonanceplate.Whenitstwopluspulsesignal,thefrequencyequaltotheintrinsicpiezoelectricoscillationfrequencychip,thechipwillhappenpiezoelectricresonance,andpromotethedevelopmentofplatevibrationresonance,ultrasoundisgenerated.Conversely,ifthetwoarenotinter-electrodevoltage,whentheboardreceivedultrasonicresonance,itwillbeforvibrationsuppressionofpiezoelectricchip,themechanicalenergyisconvertedtoelectricalsignals,thenitbecomestheultrasonicreceiver.Thetraditionalwaytodeterminethemomentoftheechosarrivalisbasedonthresholdingthereceivedsignalwithafixedreference.Thethresholdischosenwellabovethenoiselevel,whereasthemomentofarrivalofanechoisdefinedasthefirstmomenttheechosignalsurpassesthatthreshold.Theintensityofanechoreflectingfromanobjectstronglydependsontheobjectsnature,sizeanddistancefromthesensor.Further,thetimeintervalfromtheechosstartingpointtothemomentwhenitsurpassesthethresholdchangeswiththeintensityoftheecho.Asaconsequence,aconsiderableerrormayoccurEventwoechoeswithdifferentintensitiesarrivingexactlyatthesametimewillsurpassthethresholdatdifferentmoments.Thestrongeronewillsurpassthethresholdearlierthantheweaker,soitwillbeconsideredasbelongingtoanearerobject.2.2.Theprincipleofultrasonicdistancemeasurement第4页Ultrasonictransmitterinadirectiontolaunchultrasound,inthemomenttolaunchthebeginningoftimeatthesametime,thespreadofultrasoundintheair,obstaclesonhiswaytoreturnimmediately,theultrasonicreflectedwavereceivedbythereceiverimmediatelystoptheclock.Ultrasoundintheairasthepropagationvelocityof340m/s,accordingtothetimerrecordsthetimet,wecancalculatethedistancebetweenthelaunchdistancebarrier(s),thatis:s=340t/2.3.40kHzultrasonicpulsegeneratedwiththelaunchRangingsystemusingtheultrasonicsensorofpiezoelectricceramicsensorsUCM40,itsoperatingvoltageofthepulsesignalis40kHz,whichbythesingle-chipimplementationofthefollowingprocedurestogenerate.puzel:mov14h,#12h;ultrasonicfiringcontinued200mshere:cplp1.0;output40kHzsquarewaveRanginginfrontofsingle-chipterminationcircuitP1.0inputport,singlechipimplementationoftheaboveprocedure,theP1.0portina40kHzpulseoutputsignal,afteramplificationtransistorT,thedrivetolaunchthefirstultrasonicUCM40T,issued40kHzultrasonicpulse,andthecontinuedlaunchof200ms.Rangingtherightandtheleftsideofthecircuit,respectively,theninputportP1.1andP1.2,theworkingprincipleandcircuitinfrontofthesamelocation.3.1.ReceptionandprocessingofultrasonicUsedtoreceivethefirstlaunchofthefirstpairUCM40R,theultrasonicpulsemodulationsignalintoanalternatingvoltage,theop-ampamplificationIC1AandafterpolarizationIC1BtoIC2.IC2islockedloopwithaudiodecoderchipLM567,internalvoltage-controlledoscillatorcenterfrequencyoff0=1/1.1R8C3,capacitorC4determinetheirtargetbandwidth.R8-conditioninginthelaunchofthecarrierfrequencyontheLM567inputsignalisgreaterthan25mV,theoutputfromthehighjump8feetintoalow-level,第5页asinterruptrequestsignalstothesingle-chipprocessing.Ranginginfrontofsingle-chipterminationcircuitoutputportINT0interruptthehighestpriority,rightorleftlocationoftheoutputcircuitwithoutputgateIC3AaccessINT1portsingle-chip,whilesingle-chipP1.3andP1.4receivedinputIC3A,interruptedbytheprocesstoidentifythesourceofinquirytodealwith,interruptprioritylevelforthefirstleftrightafter.Partofthesourcecodeisasfollows:receive1:pushpswpushaccclrex1;relatedexternalinterrupt1jnbp1.1,right;P1.1pinto0,rangingfromrighttointerruptserviceroutinecircuitjnbp1.2,left;P1.2pinto0,totheleftrangingcircuitinterruptserviceroutinereturn:SETBEX1;openexternalinterrupt1popaccpoppswretiright:.;rightlocationentrancecircuitinterruptserviceroutineAjmpReturnleft:.;leftRangingentrancecircuitinterruptserviceroutineAjmpReturn3.2.ThecalculationofultrasonicpropagationtimeWhenyoustartfiringatthesametimestartthesingle-chipcircuitrywithinthetimerT0,theuseoftimercountingfunctionrecordsthetimeandthelaunchofultrasonicreflectedwavereceivedtime.Whenyoureceivetheultrasonicreflectedwave,thereceivercircuitoutputsanegativejumpintheendofINT0orINT1interruptrequestgeneratesasignal,single-chipmicrocomputerinresponsetoexternalinterruptrequest,theimplementationoftheexternalinterruptservicesubroutine,readthetimedifference,calculatingthedistance.Someofitssourcecodeisasfollows:第6页RECEIVE0:PUSHPSWPUSHACCCLREX0;relatedexternalinterrupt0MOVR7,TH0;readthetimevalueMOVR6,TL0CLRCMOVA,R6SUBBA,#0BBH;calculatethetimedifferenceMOV31H,A;storageresultsMOVA,R7SUBBA,#3CHMOV30H,ASETBEX0;openexternalinterrupt0POPACCPOPPSWRETIForaflattarget,adistancemeasurementconsistsoftwophases:acoarsemeasurementand.afinemeasurement:Step1:Transmissionofonepulsetraintoproduceasimpleultrasonicwave.Step2:Changingthegainofbothechoamplifiersaccordingtoequation,untiltheechoisdetected.Step3:Detectionoftheamplitudesandzero-crossingtimesofbothechoes.Step4:Settingthegainsofbothechoamplifierstonormalizetheoutputat,say3volts.Settingtheperiodofthenextpulsesaccordingtothe:periodofechoes.Settingthetimewindowaccordingtothedataofstep2.Step5:Sendingtwopulsetrainstoproduceaninterferedwave.Testingthezero-crossingtimesandamplitudesoftheechoes.Ifphaseinversionoccursintheecho,determinetootherwisecalculatetobyinterpolationusingtheamplitudesnearthetrough.Derivetsubm1andtsubm2.Step6:Calculationofthedistanceyusingequation.第7页4.TheultrasonicrangingsystemsoftwaredesignSoftwareisdividedintotwoparts,themainprogramandinterruptserviceroutine.Completionoftheworkofthemainprogramisinitialized,eachsequenceofultrasonictransmittingandreceivingcontrol.Interruptserviceroutinesfromtimetotimetocompletethreeoftherotationdirectionofultrasoniclaunch,themainexternalinterruptservicesubroutinetoreadthevalueofcompletiontime,distancecalculation,theresultsoftheoutputandsoon.5.ConclusionsRequiredmeasuringrangeof30cm200cmobjectsinsidetheplanetodoanumberofmeasurementsfoundthatthemaximumerroris0.5cm,andgoodreproducibility.Single-chipdesigncanbeseenontheultrasonicrangingsystemhasahardwarestructureissimple,reliable,smallfeaturessuchasmeasurementerror.Therefore,itcanbeusednotonlyformobilerobotcanbeusedinotherdetectionsystems.第8页中文翻译稿超声测距系统设计超声测距技术在工业现场、车辆导航、水声工程等领域都具有广泛的应用价值，目前已应用于物位测量、机器人自动导航以及空气中与水下的目标探测、识别、定位等场合。因此，深入研究超声的测距理论和方法具有重要的实践意义。为了进一步提高测距的精确度，满足工程人员对测量精度、测距量程和测距仪使用的要求，本文研制了一套基于单片机的便携式超声测距系统。1.前言随着科技的发展，人们生活水平的提高，城市发展建设加快，城市给排水系统也有较大发展，其状况不断改善。但是，由于历史原因合成时间住的许多不可预见因素，城市给排水系统，特别是排水系统往往落后于城市建设。因此，经常出现开挖已经建设好的建筑设施来改造排水系统的现象。城市污水给人们带来了困扰，因此箱涵的排污疏通对大城市给排水系统污水处理，人们生活舒适显得非常重要。而设计研制箱涵排水疏通移动机器人的自动控制系统，保证机器人在箱涵中自由排污疏通，是箱涵排污疏通机器人的设计研制的核心部分。控制系统核心部分就是超声波测距仪的研制。因此，设计好的超声波测距仪就显得非常重要。精密机床必须校准。在过去，这已经完成利用机械设备，如卡钳，微米等。不过，使用这种装置并不容易本身自动化技术。据了解，该两点之间距离才能确定通过测量传播时间的浪潮往返那些两点。这样一个类型的波是一种超声波，或声，海浪。当超声波旅行两点之间，距离两个点之间可以衡量乘以过境的时间波由波速，在中期分开两点。第9页因此，这是一个对象本发明提供仪器利用超声波准确测量两点之间距离。当中等两个点之间的间距是被衡量的是空气，声速是取决于温度和空气相对湿度。因此，它是进一步对象的，现在的发明，提供仪器的类型所描述的是独立于温度和湿度的变化。2.超声波测距原理2.1.压电式超声波发生器原理压电式超声波发生器实际上是利用压电晶体的谐振来工作的。超声波发生器内部结构，它有两个压电晶片和一个共振板。当它的两极外加脉冲信号，其频率等于压电晶片的固有振荡频率时，压电晶片将会发生共振，并带动共振板振动，便产生超声波。反之，如果两电极间未外加电压，当共振板接收到超声波时，将压迫压电晶片作振动，将机械能转换为电信号，这时它就成为超声波接收器了。测量脉冲到达时间的传统方法是以拥有固定参数的接收信号开端为基础的。这个界限恰恰选于噪音水平之上，然而脉冲到达时间被定义为脉冲信号刚好超过界限的第一时刻。一个物体的脉冲强度很大程度上取决于这个物体的自然属性尺寸还有它与传感器的距离。进一步说，从脉冲起始点到刚好超过界限之间的时间段随着脉冲的强度而改变。结果，一种错误便出现了两个拥有不同强度的脉冲在不同时间超过界限却在同一时间到达。强度较强的脉冲会比强度较弱的脉冲超过界限的时间早点，因此我们会认为强度较强的脉冲属于较近的物体。2.2.超声波测距原理超声波发射器向某一方向发射超声波，在发射时刻的同时开始计时，超声波在空气中传播，途中碰到障碍物就立即返回来，超声波接收器收到反射波就立即停止计时。超声波在空气中的传播速度为340m/s，根据计时器记录的时间t，就可以计算出发射点距障碍物的距离(s)，即：s=340t/2。3.40kHz脉冲的产生与超声波发射测距系统中的超声波传感器采用UCM40的压电陶瓷传感器，它的工作电压是40kHz的脉冲信号，这由单片机执行下面程序来产生。puzel：mov14h,#12h；超声波发射持续200mshere：cplp1.0；输出40kHz方波nop；第10页nop；nop；djnz14h，here；ret前方测距电路的输入端接单片机P1.0端口，单片机执行上面的程序后，在P1.0端口输出一个40kHz的脉冲信号，经过三极管T放大，驱动超声波发射头UCM40T，发出40kHz的脉冲超声波，且持续发射200ms。右侧和左侧测距电路的输入端分别接P1.1和P1.2端口，工作原理与前方测距电路相同。3.1.超声波