外文翻译--电子动力转向系统的研究与设计.doc

1电气与信息学院自动化专业毕业设计（论文）外文翻译ElectonicpowersteeringsystemResearchandDesign电子动力转向系统的研究与设计注：本毕业设计（论文）外文翻译文档前半部分为英文部分，后半部分为中文部分。本外文翻译由专业人员翻译，内容详细数据全面，得到导师的一致好评。值得大家借鉴参考。本文档下载后为WORD版本，可按需直接编辑。2ElectronicpowersteeringsystemWhatitisElectricallypoweredsteeringusesanelectricmotortodriveeitherthepowersteeringhydraulicpumporthesteeringlinkagedirectly.Thepowersteeringfunctionisthereforeindependentofenginespeed,resultinginsignificantenergysavings.Howitworks:Conventionalpowersteeringsystemsuseanengineaccessorybelttodrivethepump,providingpressurizedfluidthatoperatesapistoninthepowersteeringgearoractuatortoassistthedriver.Inelectro-hydraulicsteering,oneelectricallypoweredsteeringconceptusesahighefficiencypumpdrivenbyanelectricmotor.Pumpspeedisregulatedbyanelectriccontrollertovarypumppressureandflow,providingsteeringeffortstailoredfordifferentdrivingsituations.Thepumpcanberunatlowspeedorshutofftoprovideenergysavingsduringstraightaheaddriving(whichismostofthetimeinmostworldmarkets).Directelectricsteeringusesanelectricmotorattachedtothesteeringrackviaagearmechanism(nopumporfluid).Avarietyofmotortypesandgeardrivesispossible.Amicroprocessorcontrolssteeringdynamicsanddrivereffort.Inputsincludevehiclespeedandsteering,wheeltorque,angularpositionandturningrate.WorkingInDetail:Asteeringsensorislocatedontheinputshaftwhereitentersthegearboxhousing.Thesteeringsensorisactuallytwosensorsinone:atorquesensorthatconvertssteeringtorqueinputanditsdirectionintovoltagesignals,andarotationsensorthatconvertstherotationspeedanddirectionintovoltagesignals.Aninterfacecircuitthatsharesthesamehousingconvertsthesignalsfromthe3torquesensorandrotationsensorintosignalsthecontrolelectronicscanprocess.Inputsfromthesteeringsensoraredigestedbyamicroprocessorcontrolunitthatalsomonitorsinputfromthevehiclesspeedsensor.Thesensorinputsarethencomparedtodeterminehowmuchpowerassistisrequiredaccordingtoapreprogrammedforcemapinthecontrolunitsmemory.Thecontrolunitthensendsouttheappropriatecommandtothepowerunitwhichthensuppliestheelectricmotorwithcurrent.Themotorpushestheracktotherightorleftdependingonwhichwaythevoltageflows(reversingthecurrentreversesthedirectionthemotorspins).Increasingthecurrenttothemotorincreasestheamountofpowerassist.Thesystemhasthreeoperatingmodes:anormalcontrolmodeinwhichleftorrightpowerassistisprovidedinresponsetoinputfromthesteeringtorqueandrotationsensorsinputs；areturncontrolmodewhichisusedtoassiststeeringreturnaftercompletingaturn；andadampercontrolmodethatchangeswithvehiclespeedtoimproveroadfeelanddampenkickback.Ifthesteeringwheelisturnedandheldinthefull-lockpositionandsteeringassistreachesamaximum,thecontrolunitreducescurrenttotheelectricmotortopreventanoverloadsituationthatmightdamagethemotor.Thecontrolunitisalsodesignedtoprotectthemotoragainstvoltagesurgesfromafaultyalternatororchargingproblem.Theelectronicsteeringcontrolunitiscapableofself-diagnosingfaultsbymonitoringthesystemsinputsandoutputs,andthedrivingcurrentoftheelectricmotor.Ifaproblemoccurs,thecontrolunitturnsthesystemoffbyactuatingafail-saferelayinthepowerunit.Thiseliminatesallpowerassist,causingthesystemtorevertbacktomanualsteering.AdashEPSwarninglightisalsoilluminatedtoalertthedriver.Todiagnosetheproblem,atechnicianjumpstheterminalsontheservicecheckconnectorandreadsoutthetroublecodes.4clickheretoseeabiggerElectricpowersteeringsystemspromiseweightreduction,fuelsavingsandpackageflexibility,atnocostpenalty.Europeshighfuelpricesandsmallervehiclesmakeafertiletestbedforelectricsteering,atechnologythatpromisesautomakersweightsavingsandfueleconomygains.Andinashorttime,electricsteeringwillmakeittotheU.S.,too.Itsjustjustamatteroftime,saysAlyBadawy,directorofresearchanddevelopmentforDelphiSaginawSteeringSystemsinSaginaw,Mich.Theissuewascostandthatsbehindusnow.By2002hereintheU.S.thecostofelectricpowersteeringwillabsolutelybeawashoverhydraulic.Today,electricandhybrid-poweredvehicles(EV),includingToyotasPriusandGMsEV-1,aretheperfectdomainforelectricsteering.Butby2010,aTRWIernalstudyestimatesthatoneoutofeverythreecarsproducedintheworldwillbeequippedwithsomeformofelectrically-assistedsteering.TheCleveland-basedsupplierclaimsitsnewsteeringsystemscouldimprovefueleconomybyupto2mpg,whileenhancinghandling.Therearetruebottom-linebenefitsaswellforautomakersbyreducingoverallcostsanddecreasingassemblytime,sincetheresnoneedforpumps,hosesandfluids.Anotherclaimedadvantageisshorteneddevelopmenttime.Forinstance,aDelphigroupdevelopedE-TUNE,aride-and-handlingsoftwarepackagethatcanberunoffalaptopcomputer.Theycantakethatcomputerandplugitin,attachittothecontrollerandchangeallthehandlingparameters-effortlevel,returnability,damping-onthefly,Badawysays.Itusedtotakemonths.DelphihasoneOEMcustomerthatshouldstartlow-volumeproducti