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:A"steeringsensor"islocatedontheinputshaftwhereitentersthegearboxhousing.Thesteeringsensorisactuallytwosensorsinone:a"torquesensor"thatconvertssteeringtorqueinputanditsdirectionintovoltagesignals,anda"rotationsensor"thatconvertstherotationspeedanddirectionintovoltagesignals.An"interface"circuitthatsharesthesamehousingconvertsthesignalsfromthe3torquesensorandrotationsensorintosignalsthecontrolelectronicscanprocess.Inputsfromthesteeringsensoraredigestedbyamicroprocessorcontrolunitthatalsomonitorsinputfromthevehiclesspeedsensor.Thesensorinputsarethencomparedtodeterminehowmuchpowerassistisrequiredaccordingtoapreprogrammed"forcemap"inthecontrolunitsmemory.Thecontrolunitthensendsouttheappropriatecommandtothe"powerunit"whichthensuppliestheelectricmotorwithcurrent.Themotorpushestheracktotherightorleftdependingonwhichwaythevoltageflows(reversingthecurrentreversesthedirectionthemotorspins).Increasingthecurrenttothemotorincreasestheamountofpowerassist.Thesystemhasthreeoperatingmodes:a"normal"controlmodeinwhichleftorrightpowerassistisprovidedinresponsetoinputfromthesteeringtorqueandrotationsensorsinputs;a"return"controlmodewhichisusedtoassiststeeringreturnaftercompletingaturn;anda"damper"controlmodethatchangeswithvehiclespeedtoimproveroadfeelanddampenkickback.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,aTRWInc.internalstudyestimatesthatoneoutofeverythreecarsproducedintheworldwillbeequippedwithsomeformofelectrically-assistedsteering.TheCleveland-basedsupplierclaimsitsnewsteeringsystemscouldimprovefueleconomybyupto2mpg,whileenhancinghandling.Therearetruebottom-linebenefitsaswellforautomakersbyreducingoverallcostsanddecreasingassemblytime,sincetheresnoneedforpumps,hosesandfluids.Anotherclaimedadvantageisshorteneddevelopmenttime.Forinstance,aDelphigroupdevelopedE-TUNE,aride-and-handlingsoftwarepackagethatcanberunoffalaptopcomputer."Theycantakethatcomputerandplugitin,attachittothecontrollerandchangeallthehandlingparameters-effortlevel,returnability,damping-onthefly,"Badawysays."Itusedtotakemonths."DelphihasoneOEMcustomerthatshouldstartlow-volumeproductionin99.Electricsteeringunitsarenormallyplacedinoneofthreepositions:column-drive,pinion-driveandrack-drive.Whichsystemwillbecomethenormisstillunclear.Shortterm,OEMswillchoosethesteeringsystemthatiseasiesttointegrateintoanexistingplatform.Obviously,