自动抄表外文翻译解析

河北建筑工程学院本科毕业设计（论文）外文资料翻译院别：电气工程学院专业：电气工程及其自动化班级：电控102姓名：白宇学号：2010308233外文出处：CNKI（用外文写）附件：1、外文原文；2、外文资料翻译译文。指导教师评语：签字：年月日1、外文原文AutomaticmeterreadingsystemThepresentinventionrelatestoautomaticmeterreading.Moreparticularly,thepresentinventionrelatestoanautomatedsystemforremotelymonitoringapluralityofutilitymetersoncommandfromahostserverviaanRFoutboundbroadcast.BACKGROUNDOFTHEINVENTIONHistorically,metersmeasuringelectricalenergy,waterflow,gasusage,andthelikehaveusedmeasurementdevices,whichmechanicallymonitorthesubscriber'susageanddisplayareadingoftheusageatthemeteritself.Consequently,thereadingofthesemetershasrequiredthathumanmeterreadersphysicallygotothesiteofthemeterandmanuallydocumentthereadings.Clearly,thisapproachreliesveryheavilyonhumaninterventionand,thus,isverycostly,time-consuming,andpronetohumanerror.Asthenumberofmetersinatypicalutility'sserviceregionhasincreased,insomecasesintothemillions,humanmeterreadinghasbecomeprohibitiveintermsoftimeandmoney.Inresponse,varioussensingdeviceshavebeendevelopedtoautomaticallyreadutilitymetersandstorethemeterdataelectronically.Thesesensingdevices,usuallyoptical,magnetic,orphotoelectricinnature,arecoupledtothemetertorecordthemeterdata.Additionally,themetershavebeenequippedwithradiofrequency(RF)transceiversandcontroldeviceswhichenablethemeterstotransmitmeterdataoveranRFlinkwhenrequestedtodoso.Hand-helddeviceshavebeendevelopedwhichincludeRFtransceiversdesignedtointerfacewiththemeters'RFtransceivers.Thesehand-helddevicesenablethehumanmeterreadertosimplywalkbythemeter'slocation,transmitareadingrequestoveranRFlinkfromthehand-helddevicetothemeter'sreceivingdevice,waitforaresponsefromthemeter'ssensingandtransmittingdevice,andthenrecord,manuallyorelectronically,themeterdata.Similarly,meterreadingdeviceshavebeendevelopedfordrive-byreadingsystems.UtilityvansareequippedwithRFtransceiverssimilartothosedescribedinthehand-heldexampleabove.Thehumanmeterreaderdrivesbythesubscriber'slocation,withanautomatedreadingsystemintheutilityvan.Again,themetersarecommandedtoreportthemeterdata,whichisreceivedinthevanviaanRFlink,wherethedataisrecordedelectronically.Whilethismethodologyimprovesuponthepreviousapproaches,itstillrequiresasignificantamountofhumaninterventionandtime.Recently,therehasbeenaconcertedefforttoaccomplishmeterreadingbyinstallingfixedcommunicationnetworksthatwouldallowdatatoflowfromthemeterallthewaytothehostsystemwithouthumanintervention.Thesefixedcommunicationsnetworkscanoperateusingwirelineorradiotechnology.FIG.1showsaconventionalfixedcommunicationnetworkforautomatedmeterreading(AMR)technology.AsshowninFIG.1,afixedcommunicationnetworkhavingwirelinetechnologyinwhichutilitymeters10areconnectedtoawideareanetwork(WAN)consistingofasuitablecommunicationsmedium,includingordinarytelephonelines,orthepowerlinesthatfeedthemetersthemselves.Onedisadvantageofthisapproachhasbeenthatwhenanumberofmeterstransmitmeterdatanearlysimultaneously,theinherentlatencyonthewideareanetworkresultsinpacketcollisions,lostdata,garbleddata,andgeneraldegradationofintegrityacrossthesystem.Tocompensateforthecollisionsandinterferencebetweendatapackagesdestinedforthecentralcomputer,duetothelatencyinherentintheWAN,variousmanagementschemeshavebeenemployedtoensurereliabledeliveryofthemeterdata.However,whilethisapproachmaybesuitableforsmallsystems,itdoesnotservetheneedsofautilitywhichmonitorsthousandsorevenmillionsofmeters.InanattempttobettermanagethetrafficintheWAN,approacheshavebeendevelopedwhereinmetercontroldevicessimilartothosedescribedabovehavebeenprogrammedtotransmitmeterdatainresponsetocommandsreceivedfromthecentralcomputerviatheWAN.Bylimitingthenumberofmeterreadingcommandstransmittedatagiventime,thecentralcomputercontrolsthevolumeofdatatransmittedsimultaneously.However,theadditionalWANtrafficfurtheraggravatedthedegradationofdataintegrityduetovariousWANlatencyeffects.Thus,whiletheseapproachesmayservetoeliminatetheneedforhumanmeterreaders,relianceontheWANhasproventheseapproachestobeunsatisfactoryforservicingthenumberofmetersinthetypicalserviceregion.Consequently,radiotechnologyhastendedtobethemediumofchoiceduetoitshigherdataratesandindependenceofthedistributionnetwork.ThelatestevolutionofautomatedmeterreadingsystemshavemadeuseofoutboundRFcommunicationsfromafixedsource(usuallytheutility'scentralstation),directlytoRFreceiversmountedonthemeters.Themetersarealsoequippedwithcontroldeviceswhichinitiatethetransferofmeterdatawhencommandedtodosobythefixedsource.ThemetersrespondviaaWANasinthepreviouswire-basedexample.OnedisadvantageoftheseapproachesisthatthereisstillfartoomuchinterferenceontheWANwhenallofthemetersrespondataboutthesametime.Thus,whiletheseapproachesreducesomeoftheWANtraffic(byeliminatingoutboundcommandsovertheWAN),theyarestillunabletoaccommodatethelargenumberofmetersbeingpolled.Itisworthyofnotethatthewire-basedsystemstypicallyuseasinglefrequencychannelandallowtheimpedanceandtransfercharacteristicsofthetransformersinthesubstationtopreventinjectionequipmentinonestationfrominterferingwithreceiversinanothersta