基于MATLAB的智能多輸入多輸出智能解耦系統(tǒng)設(shè)計(jì)仿真

洛陽(yáng)理工學(xué)院畢業(yè)設(shè)計(jì)（論文）洛陽(yáng)理工學(xué)院畢業(yè)設(shè)計(jì)（論文）#結(jié)論本課題屬于交叉學(xué)科，相對(duì)于其它課題而言綜合性比較大。本文提出

了一種多輸入多輸出的智能解耦控制系統(tǒng)基于 MATLAB，并采用了許多新的知識(shí)和新的研究結(jié)果在學(xué)術(shù)領(lǐng)域上。在最后實(shí)驗(yàn)的調(diào)試中，系統(tǒng)表現(xiàn)出運(yùn)行可靠，測(cè)量的數(shù)據(jù)也較為準(zhǔn)確，能夠滿足現(xiàn)代化農(nóng)業(yè)科學(xué)生產(chǎn)和現(xiàn)代化管理的要求?？傮w看來(lái)，本系統(tǒng)具有如下特點(diǎn) ：本系統(tǒng)采用了模糊解耦控制技術(shù)，使溫室大棚內(nèi)溫度和濕度的調(diào)節(jié)可以達(dá)到理想的控制效果。與傳統(tǒng)的溫室環(huán)境控制技術(shù)相比較，使得系統(tǒng)的運(yùn)行費(fèi)用有了一定的減少，能夠節(jié)約很多的人力和物力資源，減少了資源浪費(fèi)，也對(duì)溫室的能源起到了一定的節(jié)約。在軟件方面，用的是MATLAB進(jìn)行的系統(tǒng)仿真設(shè)計(jì)，不但能增加測(cè)量和控制過程的穩(wěn)定性，而且還能避免因人失誤而導(dǎo)致的讀取數(shù)據(jù)和進(jìn)行技術(shù)時(shí)的誤差。本系統(tǒng)擁有很好的圖形界面，結(jié)果一目了然，操作起來(lái)也很方便。本課題僅僅是在溫室的溫濕度之間的智能解耦控制方面進(jìn)行了一定研究和仿真，由于時(shí)間的倉(cāng)促和實(shí)驗(yàn)條件的不完善，還有很多細(xì)節(jié)存在一定的不足需要進(jìn)一步的研究和學(xué)習(xí)。并且本系統(tǒng)主要以溫室大棚秋季的溫度和濕度調(diào)控為研究對(duì)象，研究的范圍不完整，應(yīng)該選取一年中各個(gè)季節(jié)進(jìn)行全面的研究，這樣可以使得控制范圍更廣泛更具有應(yīng)用性，在農(nóng)業(yè)中推廣起來(lái)也更可靠。謝辭經(jīng)過本課題是在指導(dǎo)教師XX的細(xì)心教導(dǎo)和不斷督促與監(jiān)督下完成的。幾個(gè)月的斷斷續(xù)續(xù)的學(xué)習(xí)和交流，我學(xué)到了很多東西，這些都是以往在大學(xué)課堂上不愿意去學(xué)習(xí)但是又對(duì)我的未來(lái)有很大幫助的東西，對(duì)于老師給我的幫助在這里我想表達(dá)對(duì)她的真誠(chéng)的謝意。在本課題的開題過程和中期檢查中，還得到了眾多同學(xué)和老師的熱心指導(dǎo)和幫助，在此表示誠(chéng)摯的感謝。經(jīng)過最后，再次特別感謝我的導(dǎo)師 XX老師，還有那些無(wú)私幫助我的同學(xué),他們?cè)谡n題的進(jìn)展、學(xué)習(xí)、研究和仿真設(shè)計(jì)中給我的幫助和照顧，這些都是我完成本課題的源動(dòng)力和后背力量。參考文獻(xiàn)盧佩，劉效勇?溫室大棚溫濕度模糊解耦控制系統(tǒng)設(shè)計(jì)與仿真 ?農(nóng)機(jī)化研究，2010（1）:44-47黃力櫟，胡斌，羅昕?溫濕度解耦模糊控制系統(tǒng)的研究 ?農(nóng)機(jī)化研究，2010（2）:56-59朱虹.基于模型的溫室環(huán)境控制算法研究 .南京：東南大學(xué)，2005師黎.智能控制實(shí)驗(yàn)與綜合設(shè)計(jì)指導(dǎo) .北京：清華大學(xué)出版社，2008張瑞華.溫室環(huán)境自動(dòng)監(jiān)控?計(jì)算機(jī)與農(nóng)業(yè),2002（2）：8-10馮冬青，謝宋和等?模糊智能控制?北京：化學(xué)業(yè)出版社， 2003魯燕，何曉娥，陸海燕，李萍萍.我國(guó)精確農(nóng)業(yè)發(fā)展?fàn)顩r及前景展望 ?江蘇農(nóng)機(jī)與農(nóng)藝， 2004，30（3）:8-10張?jiān)?模糊數(shù)學(xué)在自動(dòng)化技術(shù)中的應(yīng)用 .北京：清華大學(xué)出版社，2003鄧璐娟.智能溫室的模型和控制策略研究 .上海：上海大學(xué)，2004楊汝清.智能控制工程.上海：上海交通大學(xué)出版社， 2001孫優(yōu)賢.多變量解耦控制系統(tǒng).浙江大學(xué)學(xué)報(bào)，1980（3）：17-19章衛(wèi)國(guó)，楊向忠■模糊控制理論與應(yīng)用 .西北工業(yè)大學(xué)出版社，1999王濤，王艷平等■模糊控制系統(tǒng)的設(shè)計(jì)及穩(wěn)定性分析 .科學(xué)出版社，2004李秋紅，葉志峰，徐愛民.自動(dòng)控制原理實(shí)驗(yàn)指導(dǎo).國(guó)防工業(yè)出版社，2007王沫然，陳懷坤.Simulink4建模及動(dòng)態(tài)仿真.電子工業(yè)出版社，2002MohandMokhtari.MATLAB與Simulink工程應(yīng)用.電子工業(yè)出版社，2002陳曉平，李長(zhǎng)杰.MATLAB及其在電路與控制理論中的應(yīng)用 .中國(guó)科學(xué)技大學(xué)出版社， 2004石辛民.模糊控制及MATLAB仿真.北京：清華大學(xué)出版社,2008外文資料翻譯UltrasonicdistancemeterDocument Typeand Number:United StatesPatent5442592Abstract:Anultrasonicdistaneemetercancelsouttheeffectsoftemperatureandhumidityvariationsbyincludingameasuringunitandareferenceunit.Ineachoftheunits,arepetitiveseriesofpulsesisgenerated,eachhavingarepetition ratedirectlyrelatedtotherespectivedistancebetweenanelectroacoustictransmitterandanelectroacousticreceiver.Thepulsetrainsareprovidedtorespectivecounters,andtheratioofthecounteroutputsisutilizedtodeterminethedistancebeingmeasured.PublicationDate:08/15/1995PrimaryExaminer:Lobo,lanJ.BACKGROUNDOFTHEINVENTIONThisinventionrelatestoapparatusforthemeasurementofdistanceand,moreparticularly,tosuchapparatuswhichtransmitsultrasonicwavesbetweentwopoints.Precisionmachinetoolsmustbecalibrated.Inthepast,thishasbeenaccomplishedutilizingmechanicaldevicessuchascalipers,micrometers,andthelike.However,theuseofsuchdevicesdoesnotreadilylenditselftoautomationtechniques.Itisknownthatthedistancebetweentwopointscanbedeterminedbymeasuringthepropagationtimeofawavetravellingbetweenthosetwopoints.Onesuchtypeofwaveisanultrasonic,oracoustic,wave.Whenanultrasonicwavetravelsbetweentwopoints,thedistancebetweenthetwopointscanbemeasuredbymultiplyingthetransittimeofthewavebythewavevelocityinthemediumseparatingthetwopoints.Itisthereforeanobjectofthepresentinventiontoprovideapparatusutilizingultrasonicwavestoaccuratelymeasurethedistancebetweentwopoints.Whenthemediumbetweenthetwopointswhosespacingisbeingmeasuredisair,thesoundvelocityisdependentuponthetemperatureandhumidityoftheair.Itisthereforeafurtherobjectofthe,presentinventiontoprovideapparatusofthetypedescribedwhichisindependentoftemperatureandhumidityvariations.SUMMARYOFTHEINVENTIONTheforegoingandadditionalobjectsareattainedinaccordaneewiththeprinciplesofthisinventionbyprovidingdistaneemeasuringapparatuswhichincludesarefereneeunitandameasuringunit.Therefereneeandmeasuringunitsarethesameandeachincludesanelectroacoustictransmitterandanelectroacousticreceiver.Thespacingbetweenthetransmitterandthereceiveroftherefereneeunitisafixedrefereneedistanee,whereasthespacingbetweenthetransmitterandreceiverofthemeasuringunitisthedistaneetobemeasured.Ineachoftheunits,thetransmitterandreceiverarecoupledbyafeedbackloopwhichcausesthetransmittertogenerateanacousticpulsewhichisreceivedbythereceiverandconvertedintoanelectricalpulsewhichisthenfedbacktothetransmitter,sothatarepetitiveseriesofpulsesresults.Therepetitionrateofthepulsesisinverselyrelatedtothedistaneebetweenthetransmitterandthereceiver.Ineachoftheunits,thepulsesareprovidedtoacounter.Sincetherefereneedistaneeisknown,theratioofthecounteroutputsisutilizedtodeterminethedesireddistaneetobemeasured.Sineebothcountsareidenticallyinflueneedbytemperatureandhumidityvariations,bytakingtheratioofthecounts,theresultantmeasurementbecomesinsensitivetosuchvariations.DETAILEDDESCRIPTIONA.principleofultrasoniedistaneemeasurementtheprincipleofpiezoelectricultrasonicgeneratorPiezoelectricultrasonicgeneratoristheuseofpiezoelectriccrystalresonatorstowork.Ultrasonicgenerator,theinternalstructureasshowninFigure1,ithastwopiezoelectricchipandaresonaneeplate.Whenit'stwopluspulsesignal,thefrequencyequaltotheintrinsicpiezoelectricoscillationfrequencychip,thechipwillhappenpiezoelectricresonance,andpromotethedevelopmentofplatevibrationresonance,ultrasoundisgenerated.Conversely,ifthetwoarenotinter-electrodevoltage,whentheboardreceivedultrasonicresonance,itwillbeforvibrationsuppressionofpiezoelectricchip,themechanicalenergyisconvertedtoelectricalsignals,thenitbecomestheultrasonicreceiver.Thetraditionalwaytodeterminethemomentoftheecho'sarrivalisbasedonthresholdingthereceivedsignalwithafixedreferenee.Thethresholdischosenwellabovethenoiselevel,whereasthemomentofarrivalofanechoisdefinedasthefirstmomenttheechosignalsurpassesthatthreshold.Theintensityofanechoreflectingfromanobjectstronglydependsontheobject'snature,sizeanddistaneefromthesensor.Further,thetimeintervalfromtheecho'sstartingpointtothemomentwhenitsurpassesthethresholdchangeswiththeintensityoftheecho.Asaconsequenee,aconsiderableerrormayoccurEventwoechoeswithdifferentintensitiesarrivingexactlyatthesametimewillsurpassthethresholdatdifferentmoments.Thestrongeronewillsurpassthethresholdearlierthantheweaker,soitwillbeconsideredasbelongingtoanearerobject.theprincipleofultrasonicdistaneemeasurementUltrasonictransmitterinadirectiontolaunchultrasound,inthemomenttolaunchthebeginningoftimeatthesametime,thespreadofultrasoundintheair,obstaclesonhiswaytoreturnimmediately,theultrasonicreflectedwavereceivedbythereceiverimmediatelystoptheclock.Ultrasoundintheairasthepropagationvelocityof340m/s,accordingtothetimerrecordsthetimet,wecancalculatethedistaneebetweenthelaunchdistaneebarrier(s),thatis:s=340t/2B.UltrasonicRangingSystemfortheSecondCircuitDesignSystemischaracterizedbysingle-chipmicrocomputertoeontroltheuseofultrasonictransmitterandultrasonicreceiversincethelaunchfromtimetotime,single-chipselectionof8751,eeonomic-to-use,andthechiphas4KofROM,tofacilitateprogramming.CircuitschematicdiagramshowninFigure2.Drawonlythefrontrangeofthecircuitwiringdiagram,leftandrightinfrontofRangingRangingcircuitsandthesamecircuit,itisomitted.1,40kHzultrasonicpulsegeneratedwiththelaunchRangingsystemusingtheultrasonicsensorofpiezoelectricceramicsensorsUCM40,itsoperatingvoltageofthepulsesignalis40kHz,whichbythesingle-chipimplementationofthefollowingprocedurestogenerate.puzel:mov14h,#12h;ultrasonicfiringcontinued200msRanginginfrontofsingle-chipterminationcircuitP1.0inputport,singlechipimplementationoftheaboveprocedure,theP1.0portina40kHzpulseoutputsignal,afteramplificationtransistorT,thedrivetolaunchthefirstultrasonicUCM40T,issued40kHzultrasonicpulse,andthecontinuedlaunchof200ms.Rangingtherightandtheleftsideofthecircuit,respectively,theninputportP1.1andP1.2,theworkingprincipleandcircuitinfrontofthesamelocation.2,receptionandprocessingofultrasonicUsedtoreceivethefirstlaunchofthefirstpairUCM40R,theultrasonicpulsemodulationsignalintoanalternatingvoltage,theop-ampamplificationIC1AandafterpolarizationIC1BtoIC2.IC2islockedloopwithaudiodecoderchipLM567,internalvoltage-controlledoscillatorcenterfrequencyoff0=1/1.1R8C3,capacitorC4determinetheirtargetbandwidth.R8-conditioninginthelaunchofthecarrierfrequencyontheLM567inputsignalisgreaterthan25mV,theoutputfromthehighjump8feetintoalow-level,asinterruptrequestsignalstothesingle-chipprocessing.Ranginginfrontofsingle-chipterminationcircuitoutputportINT0interruptthehighestpriority,rightorleftlocationoftheoutputcircuitwithoutputgateIC3AaccessINT1portsingle-chip,whilesingle-chipP1.3andP1.4receivedinputIC3A,interruptedbytheprocesstoidentifythesourceofinquirytodealwith,interruptprioritylevelforthefirstleftrightafter.Partofthesourcecodeisasfollows:thecalculationofultrasonicpropagationtimeWhenyoustartfiringatthesametimestartthesingle-chipcircuitrywithinthetimerTO,theuseoftimercountingfunctionrecordsthetimeandthelaunchofultrasonicreflectedwavereceivedtime.Whenyoureceivetheultrasonicreflectedwave,thereceivercircuitoutputsanegativejumpintheendofINT0orINT1interruptrequestgeneratesasignal,single-chipmicrocomputerinresponsetoexternalinterruptrequest,theimplementationoftheexternalinterruptservicesubroutine,readthetimedifferenee,calculatingthedistanee.Foraflattarget,adistaneemeasurementconsistsoftwophases:acoarsemeasurementand.afinemeasurement:Step1:Transmissionofonepulsetraintoproduceasimpleultrasonicwave.Step2:Changingthegainofbothechoamplifiersaccordingtoequation,untiltheechoisdetected.Step3:Detectionoftheamplitudesandzero-crossingtimesofbothechoes.Step4:Settingthegainsofbothechoamplifierstonormalizetheoutputat,say3volts.Settingtheperiodofthenextpulsesaccordingtothe:periodofechoes.Settingthetimewindowaccordingtothedataofstep2.Step5:Sendingtwopulsetrainstoproduceaninterferedwave.Testingthezero-crossingtimesandamplitudesoftheechoes.Ifphaseinversionoccursintheecho,determinetootherwisecalculatetobyinterpolationusingtheamplitudesnearthetrough.Derivetsubmlandtsubm2.Step6:Calculationofthedistaneeyusingequation.Fourth,theultrasonicrangingsystemsoftwaredesignSoftwareisdividedintotwoparts,themainprogramandinterruptserviceroutine,showninFigure3(a)(b)(c)below.Completionoftheworkofthemainprogramisinitialized,eachsequeneeofultrasonictransmittingandreceivingcontrol.Interruptserviceroutinesfromtimetotimetocompletethreeoftherotationdirectionofultrasoniclaunch,themainexternalinterruptservicesubroutinetoreadthevalueofcompletiontime,distaneecalculation,theresultsoftheoutputandsoon..SysteminitializationafterthestarttimerT1startscountingfrom0toenterthemainprogramtowaitfortheT1overflowintotheT1interruptserviceroutinewhenthetimeisreached;T1interruptserviceroutinewillstartanewultrasonictransmitting,thesquarewavewillbegeneratedintheP1.0pinatthesametimeopenthetimerTOtiming,inordertoavoidthediffractionofthedirectwave,thedelay1msandthen,aftertheINTOinterruptEnable;theINTOinterrupttoallowopen,ifthisoccurswhenthelowisrepresentativeofthereceivedechosignal,theinterruptrequesttoINTOinterruptserviceroutine,theINTOinterruptserviceroutinewillstopthetimerTOtiming,readthetimevalueofTOtimertotheappropriatestoragearea.settoreceiveasignofsuccess;mainprogramdetectsreceptionhallmarksofsuccess,thetemperaturesubroutineiscalled,collectingtheambienttemperaturewhentheultrasonicranging,andconvertedtheaccuratespeedofsoundstoredinRAMstorageunit;SCMcallsthedistaneecalculationsubroutine tocalculate,calculatethedistaneebetweenthesensortothetargetobject;sincethemainprogramcallsthedisplaysubroutinetodisplay;aftercompletionofthefirstlaunch,receive,display,thesystemwilldelay1OOmsre-T1setinitialvalueagainstartT1tooverflowintothenextranging.IftheobstacleistoofarbeyondtherangethatTOoverflowhasnotyetreceivedecho"ERROR"isdisplayedbacktothemainflowintoanewroundoftests.CONCLUSIONSRequiredmeasuringrangeof3Ocm~2OOcmobjectsinsidetheplanetodoanumberofmeasurementsfoundthatthemaximumerrorisO.5cm,andgoodreproducibility.Single-chipdesigncanbeseenontheultrasonicrangingsystemhasahardwarestructureissimple,reliable,smallfeaturessuchasmeasurementerror.Therefore,itcanbeusednotonlyformobilerobotcanbeusedinotherdetectionsystems.Thoughts:Asforwhythereceiverdonothavethetransistoramplifiercircuit,becausethemagnificationwell,CX20106integratedamplifier,butalsowithautomaticgaincontrollevel,magnificationto76dB,thecenterfrequencyis38kto40k,isexactlyresonantultrasonicsensorsfrequency翻譯譯文文件類型和數(shù)目：美國(guó)專利 5442592摘要：提出了一種可以抵消溫度的影響和濕度的變化的新型超聲波測(cè)距儀，包括測(cè)量單元和參考資料。在每一個(gè)單位，重復(fù)的一系列脈沖的產(chǎn)生，每有一個(gè)重復(fù)率，直接關(guān)系到各自之間的距離，發(fā)射機(jī)和接收機(jī)。該脈沖序列提供給各自的計(jì)數(shù)器，計(jì)數(shù)器的產(chǎn)出的比率，是用來(lái)確定被測(cè)量的距離。出版日期：1995年8月15日主審查員：羅保.伊恩j.一、背景發(fā)明本發(fā)明涉及到儀器的測(cè)量距離，最主要的是，這種儀器，其中兩點(diǎn)之間傳輸超聲波。精密機(jī)床必須校準(zhǔn)。在過去，這已經(jīng)利用機(jī)械設(shè)備來(lái)完成，如卡鉗，微米尺等。不過，使用這種裝置并不利于本身的自動(dòng)化技術(shù)發(fā)展。據(jù)了解，兩點(diǎn)之間的距離可以通過測(cè)量?jī)牲c(diǎn)之間的行波傳播時(shí)間的決定。這樣的一個(gè)波浪型是一種超聲波，或聲波。當(dāng)超聲波在兩點(diǎn)之間通過時(shí)，兩點(diǎn)之間的距離可以由波的速度乘以測(cè)量得到的在分離的兩點(diǎn)中波中轉(zhuǎn)的時(shí)間。因此，本發(fā)明提供儀器利用超聲波來(lái)精確測(cè)量?jī)牲c(diǎn)之間的距離對(duì)象。當(dāng)任意兩點(diǎn)之間的介質(zhì)是空氣時(shí)，聲音的速度取決于溫度和空氣的相對(duì)濕度。因此，它是進(jìn)一步的研究對(duì)象，本次的發(fā)明，提供的是獨(dú)立于溫度和濕度的變化的新型儀器。、綜述發(fā)明這項(xiàng)距離測(cè)量?jī)x器發(fā)明是根據(jù)上述的一些條件和額外的一些基礎(chǔ)原則完成的，其中包括一個(gè)參考單位和測(cè)量單位。參考和測(cè)量單位是相同的，每個(gè)包括一個(gè)超聲波發(fā)射機(jī)和一個(gè)接收機(jī)。間隔發(fā)射器和接收器的參考值是一個(gè)固定的參考距離，而間距之間的發(fā)射機(jī)和接收機(jī)的測(cè)量單位是有最小距離來(lái)衡量的。在每一個(gè)單位，發(fā)射器和接收器耦合的一個(gè)反饋回路，它會(huì)導(dǎo)致發(fā)射器產(chǎn)生超聲脈沖，這是由接收器和接收到一個(gè)電脈沖然后被反饋到發(fā)射機(jī)轉(zhuǎn)換，從而使重復(fù)系列脈沖的結(jié)果。重復(fù)率脈沖是成反比關(guān)系之間的距離發(fā)射器和接收器。在每一個(gè)單位，脈沖提供一個(gè)反饋。由于參考的距離是眾所周知的聲速，比例反產(chǎn)出是利用數(shù)學(xué)以確定所期望的距離來(lái)衡量。由于這兩方面都是相同的影響，溫度和濕度的變化，采取的比例相同，由此產(chǎn)生的測(cè)量變得準(zhǔn)確。三、詳細(xì)說明（一）超聲波測(cè)距原理1、 壓電式超聲波發(fā)生器原理壓電式超聲波發(fā)生器實(shí)際上是利用壓電晶體的諧振來(lái)工作的。超聲波發(fā)生器內(nèi)部結(jié)構(gòu)如下所示，它有兩個(gè)壓電晶片和一個(gè)共振板。當(dāng)它的兩極外加脈沖信號(hào)，其頻率等于壓電晶片的固有振蕩頻率時(shí)，壓電晶片將會(huì)發(fā)生共振，并帶動(dòng)共振板振動(dòng)，便產(chǎn)生超聲波。反之，如果兩電極間未外加電壓，當(dāng)共振板接收到超聲波時(shí)，將壓迫壓電晶片作振動(dòng)，將機(jī)械能轉(zhuǎn)換為電信號(hào)，這時(shí)它就成為超聲波接收器了。測(cè)量脈沖到達(dá)時(shí)間的傳統(tǒng)方法是以擁有固定參數(shù)的接收信號(hào)開端為基礎(chǔ)的。這個(gè)界限恰恰選于噪音水平之上，然而脈沖到達(dá)時(shí)間被定義為脈沖信號(hào)剛好超過界限的第一時(shí)刻。一個(gè)物體的脈沖強(qiáng)度很大程度上取決于這個(gè)物體的自然屬性尺寸還有它與傳感器的距離。進(jìn)一步說，從脈沖起始點(diǎn)到剛好超過界限之間的時(shí)間段隨著脈沖的強(qiáng)度而改變。結(jié)果，一種錯(cuò)誤便出現(xiàn)了一一兩個(gè)擁有不同強(qiáng)度的脈沖在不同時(shí)間超過界限卻在同一時(shí)間到達(dá)。強(qiáng)度較強(qiáng)的脈沖會(huì)比強(qiáng)度較弱的脈沖超過界限的時(shí)間早點(diǎn)，因此我們會(huì)認(rèn)為強(qiáng)度較強(qiáng)的脈沖屬于較近的物體。2、 超聲波測(cè)距原理超聲波發(fā)射器向某一方向發(fā)射超聲波，在發(fā)射時(shí)刻的同時(shí)開始計(jì)時(shí)，超聲波在空氣中傳播，途中碰到障礙物就立即返回來(lái)，超聲波接收器收到反射波就立即停止計(jì)時(shí)。超聲波在空氣中的傳播速度為 340m/s，根據(jù)計(jì)時(shí)器記錄的時(shí)間t，就可以計(jì)算出發(fā)射點(diǎn)距障礙物的距離 （s），即：s=340t/2二超聲波測(cè)距系統(tǒng)的電路設(shè)計(jì)系統(tǒng)的特點(diǎn)是利用單片機(jī)控制超聲波的發(fā)射和對(duì)超聲波自發(fā)射至接收往返時(shí)間的計(jì)時(shí)，單片機(jī)選用 8751，經(jīng)濟(jì)易用，且片內(nèi)有4K的ROM，便于編程。電路原理圖如圖所示。其中只畫出前方測(cè)距電路的接線圖，左側(cè)和右側(cè)測(cè)距電路與前方測(cè)距電路相同，故省略之。1、 40kHz脈