超声波测距中英文对照资料外文翻译文献

超声波测距毕业论文中英文对照资料外文翻译文献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了。2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：s340t/23波测距系统的电路设计系统的特点是利用单片机控制超声波的发射和对超声波自发射至接收往返时间的计时，单片机选用C51，经济易用，且片内有4K的ROM，便于编程。3.140kHz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：mov14h12h；超声波发射持续200mshere：cplp1.0；输出40kHz方波nop；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。3.2超声波的接收与处理接收头采用与发射头配对的UCM40R，将超声波调制脉冲变为交变电压信号，经IC2运算放大器IC1A和IC1B两极放大后加至IC2。是带有锁定环的音频译码集成块LM567，内部的压控振荡器的中心频率f01/1.1R8C3，电容C4决定其锁定带宽。调节R8在发射的载频上，则LM567输入信号大于25mV，输出端8脚由高电平跃变为低电平，作为中断请求信号，送至单片机处理.前方测距电路的输出端接单片机INT0端口，中断优先级最高，左、右测距电路的输出通过与门IC3A的输出接单片机INT1端口，同时单片机P1.3和P1.4接到IC3A的输入端，中断源的识别由程序查询来处理，中断优先级为先右后左。部分源程序如下：receive1：pushpswpushaccclrex1；关外部中断1jnbp1.1right；P1.1引脚为0转至右测距电路中断服务程序jnbp1.2left；P1.2引脚为0转至左测距电路中断服务程序return：SETBEX1；开外部中断1popaccpoppswretiright：...；右测距电路中断服务程序入口ajmpreturnleft：...；左测距电路中断服务程序入口ajmpreturn3.3计算超声波传播时间在启动发射电路的同时启动单片机内部的定时器T0，利用定时器的计数功能记录超声波发射的时间和收到反射波的时间。当收到超声波反射波时，接收电路输出端产生一个负跳变，在INT0或INT1端产生一个中断请求信号，单片机响应外部中断请求，执行外部中断服务子程序，读取时间差，计算距离。其部分源程序如下：RECEIVE0：PUSHPSWPUSHACCCLREX0；关外部中断0MOVR7TH0；读取时间值MOVR6TL0CLRCMOVAR6SUBBA0BBH；计算时间差MOV31HA；存储结果MOVAR7SUBBA3CHMOV30HASETBEX0；开外部中断0POPACCPOPPSWRETI对于一个平坦的目标，距离测量包括两个阶段:粗糙的测量和精细测量。第一步：脉冲的传送产生一种简单的超声波。第二步：根据公式改变回波放大器的获得量直到回拨被检测到。第三步：检测两种回波的振幅与过零时间。第四步：设置回波放大器的所得来规格输出，假定是3伏。通过脉冲的周期设置下一个脉冲。根据第二部的数据设定时间窗。第五步：发射两串脉冲产生干扰波。测量过零时间与回波的振幅。如果逆向发生在回波中，决定要不通过在低气压插入振幅。第六步：通过公式计算距离y。4波测距系统的软件设计软件分为两部分，主程序和中断服务程序。主程序完成初始化工作、各路超声波发射和接收顺序的控制。定时中断服务子程序完成三方向超声波的轮流发射，外部中断服务子程序主要完成时间值的读取、距离计算、结果的输出等工作。5对所要求测量范围30cm200cm内的平面物体做了多次测量发现，其最大误差为0.5cm，且重复性好。可见基于单片机设计的超声波测距系统具有硬件结构简单、工作可靠、测量误差小等特点。因此，它不仅可用于移动机器人，还可用在其它检测系统中。思考：至于为什么接收不用晶体管做放大电路呢，因为放大倍数搞不好，集成放大电路，还带自动电平增益控制，放大倍数为76dB，中心频率是38k到40k，刚好是超声波传感器的谐振频率。原文出处：传感器文摘布拉福德:1993年第13页摘要附:英文原文Ultrasonicrangingtechnologyhaswideusingworthinmanyfields，suchastheindustriallocale，vehiclenavigationandsonarengineering．Nowithasbeenusedinlevelmeasurement，self-guidedautonomousvehiclesfieldworkrobotsautomotivenavigation，airandunderwatertargetdetection，identification，locationandsoon．Sothereisanimportantpracticingmeaningtolearntherangingtheoryandwaysdeeply.Toimprovetheprecisionoftheultrasonicrangingsysteminhand，satisfytherequestoftheengineeringpersonnelfortherangingprecision，theboundandtheusage，aportableultrasonicrangingsystembasedonthesinglechipprocessorwasdeveloped1.Withthedevelopmentofscienceandtechnologytheimprovementofpeoplesstandardoflivingspeedingupthedevelopmentandconstructionofthecity.urbandrainagesystemhavegreatlydevelopedtheirsituationisconstantlyimproving.Howeverduetohistoricalreasonsmanyunpredictablefactorsinthesynthesisofhertimethecitydrainagesystem.Inparticulardrainagesystemoftenlagsbehindurbanconstruction.Thereforethereareoftengoodbuildingexcavationhasbeenbuildingfacilitiestoupgradethedrainagesystemphenomenon.Itbroughttothecitysewageanditiscleartothecitysewageanddrainageculvertinthesewagetreatmentsystem.comfortisveryimportanttopeopleslives.MobilerobotsdesignedtoclearthedrainageculvertandtheautomaticcontrolsystemFreesewageculvertclearguaranteerobottherobotisdesignedtocleartheculvertsewagetothecore.ControlSystemisthecorecomponentofthedevelopmentofultrasonicrangefinder.Thereforeitisveryimportanttodesignagoodultrasonicrangefinder.2.Aprincipleofultrasonicdistancemeasurement2.1TheprincipleofpiezoelectricultrasonicgeneratorPiezoelectricultrasonicgeneratoristheuseofpiezoelectriccrystalresonatorstowork.Ultrasonicgeneratortheinternalstructureasshownithastwopiezoelectricchipandaresonanceplate.Whenitstwopluspulsesignalthefrequencyequaltotheintrinsicpiezoelectricoscillationfrequencychipthechipwillhappenpiezoelectricresonanceandpromotethedevelopmentofplatevibrationresonanceultrasoundisgenerated.Converselyifthetwoarenotinter-electrodevoltagewhentheboardreceivedultrasonicresonanceitwillbeforvibrationsuppressionofpiezoelectricchipthemechanicalenergyisconvertedtoelectricalsignalsthenitbecomestheultrasonicreceiver.Thetraditionalwaytodeterminethemomentoftheechosarrivalisbasedonthresholdingthereceivedsignalwithafixedreference.Thethresholdischosenwellabovethenoiselevelwhereasthemomentofarrivalofanechoisdefinedasthefirstmomenttheechosignalsurpassesthatthreshold.Theintensityofanechoreflectingfromanobjectstronglydependsontheobjectsnaturesizeanddistancefromthesensor.Furtherthetimeintervalfromtheechosstartingpointtothemomentwhenitsurpassesthethresholdchangeswiththeintensityoftheecho.AsaconsequenceaconsiderableerrormayoccurEventwoechoeswithdifferentintensitiesarrivingexactlyatthesametimewillsurpassthethresholdatdifferentmoments.Thestrongeronewillsurpassthethresholdearlierthantheweakersoitwillbeconsideredasbelongingtoanearerobject.2.2TheprincipleofultrasonicdistancemeasurementUltrasonictransmitterinadirectiontolaunchultrasoundinthemomenttolaunchthebeginningoftimeatthesametimethespreadofultrasoundintheairobstaclesonhiswaytoreturnimmediatelytheultrasonicreflectedwavereceivedbythereceiverimmediatelystoptheclock.Ultrasoundintheairasthepropagationvelocityof340m/saccordingtothetimerrecordsthetimetwecancalculatethedistancebetweenthelaunchdistancebarriersthatis:s340t/23.UltrasonicRangingSystemfortheSecondCircuitDesignSystemischaracterizedbysingle-chipmicrocomputertocontroltheuseofultrasonictransmitterandultrasonicreceiversincethelaunchfromtimetotimesingle-chipselectionof8751economic-to-useandthechiphas4KofROMtofacilitateprogramming.CircuitschematicdiagramshowninFigure2.Figure1circuitprinciplediagram3.140kHzultrasonicpulsegeneratedwiththelaunchRangingsystemusingtheultrasonicsensorofpiezoelectricceramicsensorsUCM40itsoperatingvoltageofthepulsesignalis40kHzwhichbythesingle-chipimplementationofthefollowingprocedurestogenerate.puzel:mov14h12hultrasonicfiringcontinued200mshere:cplp1.0output40kHzsquarewavenopnopnopdjnz14hhereretRanginginfrontofsingle-chipterminationcircuitP1.0inputportsinglechipimplementationoftheaboveproceduretheP1.0portina40kHzpulseoutputsignalafteramplificationtransistorTthedrivetolaunchthefirstultrasonicUCM40Tissued40kHzultrasonicpulseandthecontinuedlaunchof200ms.RangingtherightandtheleftsideofthecircuitrespectivelytheninputportP1.1andP1.2theworkingprincipleandcircuitinfrontofthesamelocation.3.2ReceptionandprocessingofultrasonicUsedtoreceivethefirstlaunchofthefirstpairUCM40Rtheultrasonicpulsemodulationsignalintoanalternatingvoltagetheop-ampamplificationIC1AandafterpolarizationIC1BtoIC2.IC2islockedloopwithaudiodecoderchipLM567internalvoltage-controlledoscillatorcenterfrequencyoff01/1.1R8C3capacitorC4determinetheirtargetbandwidth.R8-conditioninginthelaunchofthecarrierfrequencyontheLM567inputsignalisgreaterthan25mVtheoutputfromthehighjump8feetintoalow-levelasinterruptrequestsignalstothesingle-chipprocessing.Ranginginfrontofsingle-chipterminationcircuitoutputportINT0interruptthehighestpriorityrightorleftlocationoftheoutputcircuitwithoutputgateIC3AaccessINT1portsingle-chipwhilesingle-chipP1.3andP1.4receivedinputIC3Ainterruptedbytheprocesstoidentifythesourceofinquirytodealwithinterruptprioritylevelforthefirstleftrightafter.Partofthesourcecodeisasfollows:receive1:pushpswpushaccclrex1relatedexternalinterrupt1jnbp1.1rightP1.1pinto0rangingfromrighttointerruptserviceroutinecircuitjnbp1.2leftP1.2pinto0totheleftrangingcircuitinterruptserviceroutinereturn:SETBEX1openexternalinterrupt1popaccpoppswretiright:...rightlocationentrancecircuitinterruptserviceroutineAjmpReturnleft:...leftRangingentrancecircuitinterruptserviceroutineAjmpReturn3.3ThecalculationofultrasonicpropagationtimeWhenyoustartfiringatthesametimestartthesingle-chipcircuitrywithinthetimerT0theuseoftimercountingfunctionrecordsthetimeandthelaunchofultrasonicreflectedwavereceivedtime.WhenyoureceivetheultrasonicreflectedwavethereceivercircuitoutputsanegativejumpintheendofINT0orINT1interruptrequestgeneratesasignalsingle-chipmicrocomputerinresponsetoexternalinterruptrequesttheimplementationoftheexternalinterruptservicesubroutinereadthetimedifferencecalculatingthedistance.Someofitssourcecodeisasfollows:RECEIVE0:PUSHPSWPUSHACCCLREX0;relatedexternalinterrupt0-11-MOVR7,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.4.Theultrasonicrangingsystemso