汽车专业英语课件：Development of Vehicle Technology -

汽车专业英语DevelopmentofVehicleTechnologyAmongtherecentvehicleintroductions,fourstandoutasmarkingamajorinnovativeinputtovehicledevelopment.TheMercedesA-classisasignificantadvanceinsmallcarpackagingaswellasbreakingnewgroundinsecondarysafety.Ford’sFocusbringsthecompany’s21stcenturyhard-edgestylingtoitsmostmainstreammodelandalsomarksacompletedmarketrepositioningofaclassofvehiclestartingastheMark1Escorttoavehiclerefinedenoughtocompeteintheneo-luxurysector.TheLandRoverFreelanderbringsthepriceofcomfortable4-wheeldrivevehiclesdowntorealisticlevelsandisabreakthroughinbodyoptionversatility.ProjectThrustSSCpresentstheultimateincompetitionvehiclesandgivesatasteofthetechnologiesrequiredatthelimitsofvehicle-to-groundadhesion.在最近的车辆介绍中，四个突出点作为标志着车辆发展的主要创新性输入。在小型汽车包装以及在二级安全新突破方面，梅赛德斯A-class是一个重大的进步。福特福特斯将公司的21世纪锋刃派风格作为其主流模式，同时标志着以Mark1Escort车型为一个新的市场定位，其精工制作在新的奢侈品行业具有了足够的竞争力。路虎神行者（TheLandRoverFreelander）使舒适的四轮驱动车的价位下降到可以被接受的现实水平，并且是一个在车身选择多样性上的突破。ProjectThrustSSC（SSC项目推动）提供了竞争车辆的极致，并且实现了在限制车辆地面的附着力方面的技术尝试。8.1MercedesA-classTheworld’spioneeringmanufacturer,andpossiblystillthemostprestigious,hadamomentousyearin1998,andseemedtoemergeastheseniorpartnerinDaimler-Chrysler.Itsearlierattemptstobreakintocompactcarmakinghavealsonowbornefruitintherelaunchedmoose-proofA-classwhichhasbecomepossiblytheclass-leaderincitycars.TherevisedsuspensionsystemissaidtomaketheA-classthesafestcarinitsclass.Themodifiedrearsuspensionnowhasthespecialtierod,incorporatedandallmodelsbenefitfromESP,thecompany’sElectronicStabilityProgramme,Chassiswasalsoslightlylowered,anti-rolltorqueincreasedreartrackextendedslightly,dampers/typesreplaced,suspensionstiffenedandgreaterundersteerbuiltintothehandlingdynamics.ThesandwichfloorconceptallowstheengineanddriveassemblyoftheA-class(asinFig.8-1)tobeshuntedbackunderneaththebodyintheeventofafrontalimpactratherthanpenetratingthepassengercompartment.ThisingeniouslayoutmeansthatthenewMercedesmodelsvirtuallyachievesthehighsafetystandardoftheE-class,evenintheeventofasideimpactthe‘sandwich’conceptofthedoublelayerfloor,providesclearadvantages,becausetheoccupantssitabout20centimetreshigherthaninothercars,withtheresultthattheimpactoccursbelowtheoccupantscell.Fig.8-1MercedesA-classTheA-classcompliesnotonlywiththefutureEUfrontalimpactcrashteststandardbutalsowithstrictsafetyregulationsonsideimpactsintheUSAandtheEuropeanUnion.Intermsofsafety,acarmeasuringonlyabout1000kghasanumberofbasicdisadvantagestoovercome--especiallyifitisbuiltonconventionallines.Thelowvehiclesmass,shortfront-endstructureandlimitedspaceavailableforcrumplezonesarefundamentalhandicapsthatuntilnowhaveleftlittleroominthisvehicleclassforfurtherprogressinvehiclesafety.ThissituationhasbeenrevolutionizedwiththeA-class.Themainaiminthesafetydevelopmentofthecarwastomakemaximumuseoftheshortfrontcrumplezoneinahead-oncollisionandtoclearallcomponentsthatobstructedthecrumplingprocessoutoftheway.Becauseoftherigidstructureofengineandgearbox,theyplaypracticallynopartinthedeformation,andinconventionalcompactcarstheycanbepushedbackinasingleblockthatcanintrudeintotheinteriorandinjuretheoccupants.A-class不仅符合未来欧盟正面冲击碰撞试验标准，同时也符合有严格的侧面碰撞安全条例的美国和欧盟标准。在安全方面，一辆只有约1000公斤重的汽车—尤其是如果它在传统的生产线上生产出来的，将有一些根本的缺点需要被克服。汽车质量小，前后端结构短和有限的碰撞缓冲区是根本的障碍，直到现在这类汽车在车辆安全取得进一步进展的可能空间都很小。这种情况在A-class车型上已经彻底改变了。Heretheinnovativearrangementofengineandgearboxreducetheriskoftheirformingasingleblockandthereforemakesanessentialcontributiontooccupantsafety.IntheA-class,theengineandgearboxarepositionedatananglepartlyinfrontoftheoccupantcellandpartlyunderneathit,sothatintheeventoffrontalimpacttheycanslidedownwardsratherthanstraightback.Thisispossibleduelargelytothreeunusualfeature:theuniqueinclinedconstructionoftheengineandgearbox,theshapeandinstallationofwhicharespecificallydesignedtoaccordwiththecrashprincipleoftheA-class;thedevelopmentofaframe-typeintegralsupporttoaccommodatetheengineandgearbox,whichinacrashcandisengageattwoofitseightfixingpointstherebyallowingtheengineandgearboxtoslidedownwards;thirdlythedesignofthestablefrontfloorpanel(pedalfloor)asasurfacealongwhichtheengineandgearboxcanslideintheeventofacrash.发动机和变速箱的创新性布置降低了它们形成单轮滑车的风险，因此对于车辆安全性做出了不可或缺的贡献。在A-class车型上，发动机和变速箱的布置有一定角度的倾斜，使它们一部分在驾驶员室的前面，另一部分在驾驶员室的下面，因此，在出现前端碰撞时，它们的布置会产生下滑而不是原来的直接向后。这可能主要是由于三个不同寻常的特点：独特的发动机和变速箱倾斜结构，其形状和安装是专门设计以符合A-class车型的碰撞原理；发动机和变速箱的框架式整体支撑的发展，在碰撞时可以是它的八个固定点中的两个脱离结合，使得发动机变速箱部分可以产生侧滑；第三个原因是，稳定的前踏板地板的设计，当碰撞时，可以作为发动机和变速箱的滑移表面。ThismaximumpossibledeformationlengthavailableatthefrontendoftheMercedesA-classisduesolelytothefactthattherigidengineandgearboxaredisplacedunderthepassengercellinaserioushead-oncollision.Withoutthiscapacityforevasionandtheabilityoftheengineandgearboxto‘duck’outofthedeformationarea,thefrontendoftheA-classwouldhavetobeabout25cmlongerinordertogivetheoccupantsthesamedegreeofprotection.Thefactthattheshortcrumplezonealsodoesnotsubjecttheoccupantstoseverestressesasaresultofthehigherdecelerationvaluesisduetotheretainingsystemsspeciallymatchedtothefrontendstructure.Otheradvantagesofthenewbodyconcept(asinFig.8-2)arethestraightsidemembers.Theyabsorbhighdeformationforcesrightfromstartofbodydeformationandtherebypermitmuchmorefavorabledecelerationcharacteristicsthanincarsofconventionaldesign.Asaresult,theoccupantsshareinthedecelerationofthevehicleearlierandoveralongerperiod,whichreducesthestressestowhichpassengersaresubjected.Thetriggeringthresholdofseatbelttensionlessandairbagsonthedriverandfrontpassengersidecanalsobemorepreciselydefinedthankstothelongitudinalrigidityofthebodystructure.Thefrontendstructurehasdeformationzonesonthreelevels.TheimpactenergyinthefrontareaoftheA-classiswidelydistributedoverthreeplanes:theframe-typeintegralsupport,whichservestoaccommodatethefrontaxle,engineandgearbox;thestraightsidemembersleadingtothealuminumandsteelfrontmodule;theseconduppersidememberplaneonalevelwiththeheadlamps.Sincemostfrontalimpactsareoffsetcrasheswithunilateralstressingofthefrontendstructure,therearestrongtransverseconnectionsbetweentheimpactzonesdesignedtoensurethatthedeformationareasontheoppositeside,remotefromtheimpact,arealsoinvolved.Thisproducesahomogeneousfrontendstructurewhichwillproveeffectiveinalltypesoffrontalcollision.Thefrontwheelsalsohavearoletoplayinenergyabsorption.TheyformanadditionalloadpathandinanimpactarebracedatthestablenodalpointsofA-pillarandsill.Thiseffectisparticularlyimportantinthefrequentfrontendcrasheswithoverlapononeside-theso-calledoffsetcollisions.M-Bengineershavematchedthestrengthoftheoccupantcelltothehighfrontenddeformationforce.Theraisedflatfloor,whichisweldedfrombelowtoagrid-likesupportstructure,givestheoccupantcellahighdegreeofstabilitysothatitisessentiallynotdeformedeitherinafrontalimpactorinanoffsetcrashwith40or50percentoverlap.Airbagsandbelttensionersandapolystyreneinsertinthefootwell,whichformpartofthestandardequipmentonallMercedescars,completethelistofmeasurestoprotecttheoccupants.Fromtheoutsetthe‘BigversusSmall’aspectwasaprimeconsiderationinthesafetydevelopmentoftheA-class.Inahead-oncollisioninvolvingtwocarsofdifferingmassasuitabledistributionofthedeformationloadbetweenthetwovehiclesmustbeachievedsothatthereisnodangerparticulartotheoccupantsofthesmallercar.ForsometimenowMercedes-Benzhasbeendevelopingitscarsaccordingtothisprincipleandclaimstobethefirsttotestcarsthroughcrashtestsagainstadeformablebarrier.Thistestmethod,whichwillnotbespecifiedforallnewcarsintheEuropeanUnionuntilOctober1998,permitsanespeciallyrealisticsimulationoftypicalaccidentsinvolvingoncomingtraffic,andspecifiesahead-oncollisionat56km/hand40percentoverlapagainstadeformablebarrier.TheA-classpassesthistestevenatanimpactspeedof65km/h,correspondingtoasignificantlyhighstressloading.Compatibilitymeansthatinacollisioninvolvingtwovehiclestheyshouldactivateoneanother’scrumplezonesandbecapableoftransmittingthedeformationloaduniformlytobothbodies.Forthistohappenitisnecessaryforthefrontenddeformationresistanceoflargeandsmallcarstoapproximatetooneanother.Asanexample,intheE-classthefrontendstructureofthisMercedesmodelisconstructedsothatinacrashtheimpactenergyfortheothervehicleisreduce--intelligentsafetyengineeringmeansmutualprotection.Inasmallercar,however,thedesignprincipleisjusttheopposite.BecauseofthelowermassandtheshorterfrontendtheMercedesengineersdesignedtheA-classwithanespeciallyrigidfrontendsothatinanaccidentwithanother,largeroncomingvehicleitcanactivatetheothervehicle’sdeformationzones.Inadditiontomatchingthelevelsofforce,theuniformdistributionofimpactforcesovertheentireheightandwidthofthefrontendplaysaparticularlyimportantrole.OntheA-class,thispurposeisservedbythesecondimpactplanewithitsstabletransverseconnectionstothelowersupportstructure.Eveninafrontalcollisionwithalargecar,theoccupantsofthesmalleronearenotatamajordisadvantageinthiscase.兼容性意味着在两车相撞过程中，两辆车应该能激活彼此的碰撞缓冲区，并且能够均匀地传输负载变形。为此，大型和小型汽车的前端变形阻力应该彼此接近。例如，E-class车型中，梅赛德斯这款车的前端结构的模型建立，便于在碰撞中，另一辆车的冲击能量减小—智能安全工程意味着相互保护。对一个小型汽车而言，设计原则是恰恰相反的。由于较低的质量和更短的前端，奔驰的工程师们设计A-class车型时设计了一个特别的刚性前端，所以在与另一辆车的相撞事故中，迎面行驶车辆的体型越大，就越可以较好的激活另一辆车的变形区。除了水平力的匹配，在车前端的整个高度和宽度范围，冲击力的均匀分布的影响起到一个特别重要的作用。Thestrengthsofthesandwichconceptofthecararenotconfinedtofront-endcrashes.Theyalsoapplytosideandrearimpactcollisions:inthepreciselevelwherethebodyoftheA-classisatitsstrongest,attheleveloftheload-bearingstructureforthefloor.Theoccupantsareseatedabovethisimpactlevelandarethereforeoptimallyprotect.Theloadbearingstructureofstraightcrossmembersandsidemembersisbetterabletocontainandreducetheimpactenergythaninacarofconventionalbodydesigninwhichtheimpactmostlyoccursabovethefloorstructure.TheshortcrumplezonesatthefrontoftheA-classmakeitnecessarytoactivatethebelttensionedimmediatelyafterthecrash.Asaresult,theoccupantsnotonlytakepartearlierandlongerinthedecelerationofthevehicle,buttheyalsohavealongerdistancefortheircrash-inducedforwardmovement.Theearlierthesafetybeltbuildsupitsrestrainingforce,thelongerthedistanceavailabletothebeltandbelttensionerinwhichtoarresttheforwardmovementoftheoccupants.Inthisway,theforcesunleashedontheoccupantsarelow,despitethemassivedecelerationoftheoccupantcell.Thisalsoservestocompensateforthedesigndisadvantagesofshortdeformationzonesinsmallandcompactcars.TheinnovativerestraintsystemintheA-classincludesfull-sizeairbagsfordriverandfrontpassenger.Theairbagsfittedasstandardhaveavolumeof64and130liters.Theyareoperatedbyanewpropellanttechnologywhichofferscertainadvantageswhenrecycling:thegasgeneratorforthedriver’sairbagisfilledwithanacid-freesolidpropellant,andthepassengerairbagcontainsanenvironmentallysafeliquidgasmixtureofheliumandargon.Thecarhasinertia-reelseatbeltswithbelttensionersonthefrontseats:newlydevelopedcompactbelttensionerscompensateforseatbeltslackandensurethatinacrashtheoccupantsareevenbettertiedtothepassengercellbysnuglyfittingbelts.Thebeltstrapistensionedbysmallsteelballsintheseatbeltretractorswhich,whenthebelttensionalisactivated,aresetinmotionandrotatecountertothebeltstrapshaft.Inthiswaytheyfirststopthebeltstrapandthencoilitbackupathighspeed.Thisdrivesystemhastwooutstandingadvantages:hightensioningcapacityandcompactconstructionoftheseatbeltretractor.Theinertialreelseatbeltsforthefrontseatoccupantsareheight-adjustableinthreestages.Theseatbeltretractorsofthefrontseatbeltsincorporatetorsionbarswhichinacrashareslowlydeformedfromacertainforceupwards,therebyreducingthelockingactionoftheinertialreelseatbelts.Thisreducestheriskofinjurytotheoccupantswhomoreover,thankstotheforcelimiter,cansinkverygentlyintotheairbags.Beltforcelimitersandairbagsarethusdesignedtofunctionaspartofapreciselycoordinatedsystem.ThesideairbagsinthefrontdoorsformpartofthestandardspecificationsoftheA-class.Anewlydevelopedgasgeneratorwithliquidgasfillingisalsousedforthese.M-Balsofitsbelttensionersasstandardontheouterseatsoftherearseatunit.Theseensurethatinacrashrearseatpassengersalsobenefitingoodtimefromthedecelerationofthebodystructure.Theheightadjustmentoftheinterialreelseatsbeltsfunctionsautomaticallyontherearseats.AsontheC-andE-classcars,childseatswhichfoldoutoftherearseatsatthetouchofabuttonareavailableasanoption.惯性卷筒安全带的前座乘客在三种状态下高度可调。前排座位的安全带的拉钩与扭力杆合成一体，使得在碰撞过程中特定的向上的力引起的变形较小，从而减少了惯性卷筒安全带的锁定过程。由于对于作用力的限制，这将减少乘员的风险，乘员可以沉到安全气囊中。带力限制器和安全气囊是设计并作为一个精确地协调系统工作的。前门的侧安全气囊形成了A-class的部分标准规格规范。一个新开发的气体发生器与液态气体灌装也用于这一目的。M-Balso安装了皮带张紧装置作为后座装置的外围座椅的标准件。这保证了在碰撞后座乘客也受益于良好的车身结构的减速作用。惯性卷筒安全带的高度调整可以在后排座椅上实现自动调节。在C-class和E-class车上，儿童安全带折叠在后排座椅上并且可以通过按钮进行控制，可以被选择性的安装。Forthefirst-launchedvehicle,thefrontaxlehasamodifiedMcPhersonsuspensionsystem(asinFig.8-3)withcoilsprings,twin-tubeshockabsorbersandtorsionbarstabilizer.Thesuspensioncomponentsaremountedtogetherwiththerack-and-pinionsteeringgear,engineandgearboxonaframe-typeintegralsupportthatisboltedtothebodyateightpoints.UnliketheoriginalMcPhersonsuspension,theantirollbaroftheA-classdoesnottakepartinwheellocationbutislinkedtothesuspensionstrutviaplasticsuspension:theresultsincludebetterelastokinematicsandincreasedrollingcomfort.Ridecomfortisalsoenhancedbythelow-frictionsuspensionstrutsanddamperguideunits,theTefloncoatingofthefrontbearingofthetorsionbarandthevariousnoise-dampingmeasures.Allwheellocation,suspensionanddampingcomponentshavebeenweight-optimized,suchthatengineershavebeenweight-optimized,suchthatengineershaveachievedanexceptionallygoodbalancebetweenload-bearingabilityandintrinsicweight:theeffectsofthisbalanceonlybecomeevidentinthesumofthecar’smanydetailedsolutions.Anotherconceptualadvantagethatisfeltinthehandingofthecaristhepositionofthesteeringgearinfrontofthecentreofthewheel:thislayoutisonlypossiblebecauseofthesandwichdouble-layerfloorconcept,withtheengineandgearboxlocatedpartlyunderneaththefloorpanel.Steeringresponseisimprovedbythisgeometry.AcompactservopumpforthesteeringoftheA-class,forthefirsttimeinaMercedesisnotmechanicallydrivenbutispoweredbyanelectricmotorwithelectroniccontrol.Pumpcapacitycanbeadjustedpreciselytosuitdemandandtheinstantaneoustrafficsituation.Forexample,whendrivingonthestraight,theelectricmotorrunsatreducedspeedandconsumeslessenergy.Thethree-spokesteeringwheelofthecarisanewdevelopmentandisdesignedinparticulartosatisfytheneedsoflightweightconstruction.The370millimeterdiametersteeringwheelisanaluminumpressure-casting,witharimofpolyurethanefoamcoatedinplasticorleather,dependingontheequipmentlevelandcustomeroption.Thesteeringwheelmaterialcrumplesinacontrolledwayintheeventofhigh-forcecollisionimpact.Thecompanyoptedfortrailingarmsuspensionwithcoilsprings,torsionbarstabilizerandsingle-tubegas-pressureshockabsorbers.Themainadvantageisthattrailingarmsuspensioncanbedesignedwithallitscomponentsunderneaththeloadfloor,sothatitdoesnotencroachontheinteriorspace.Theshockabsorbersandspringsarelocatedinanotherwiseunusedspaceinfrontofthewheelcenter.Withthisgeometry,thesuspensioncomponentssupportthestraightsidemembersinacrash,therebyalsoimprovingoccupantsafety.Thedynamicqualitiesoftherearsuspensionareparticularlyduetospecialtie-boltsthatcontroltheelasticdeformationofthesidemembersandcombinewiththemtoformarectangularlinkagestructure.Changesintheangleofthesidememberandwheelabouttheverticalaxisarecompensatedwithupto75percentefficiency.Thesuspensioncomponents,sidemembers,coilspringsandshockabsorbersaremountedonasuspensionsubframeinasinglecompactblockthatisfixedtothebodyworkonfoursound-proofedrubberbearings,partlywithhydraulicdamping.Therearsuspensionunitismountedwiththeaidoffourverticalassemblybolts.Noneofthesuspensioncomponentsprojectsupwardsabovethelevelofthefloor.Thetechnologyandlayoutofthebrakes,Fig8-4correspondtotheparticularfeaturesoftheA-classdrivesystemandvehicleconcept.Engineersoptedforfloating-caliperdiscbrakesatthefrontanddrumbrakesattherear,becausethiscombinationprovidesoptimalbrakingsafety,stabilityandenduranceforafront-wheeldrivecar,sayM-B.Abrakeboosterandtheanti-lockbrakingsystemprovideaddedsafety.Thedrumbrakesontherearwheelsarecharacterizedbyalightweightconstruction:thesupportingbodyforthewheelbrakecylinderandbrakeshoes,theanchorplateandbrakecylinderaremadeofaluminum.Inordertosatisfythehighsafetyrequirements,thehubsaremadeofsteelandthebrakecylindersofgreycastiron.Anautomaticadjustingsystemcompensatesforbrakepadanddrumwear.TheparkingbrakeintheA-classisoperatedmanually,usingaleverbetweenthefrontseats.Thecontrolcablesaremaintenance-free,sincetheyhaveautomaticlengthadjustment.ESPkeepstheA-classdirectionallystableandreducestheriskofskiddingwhencorneringbyselectivelyapplyingthefrontandrearbrakes.Whiledriving,theESPcomputercomparestheactualbehaviorofthevehiclewiththecalculatedsetpoints.Ifthecarisdeviatingfromthesafe‘idealline’,thesystemrespondsathighspeedwithaspeciallydevelopedlogic,bringingthecarbacktotherighttrackintwoways,firstlybythepreciselydosedbrakingofoneormorewheelsand/orbycontrollingenginetorque.Bythesemethods,ESPcorrectsbothdrivingerrorsandskiddingmovementscausedbyslipperyorwetsurfaces,loosechippingsorotherdifficultroadconditionsthatnormallygivethedriververylittlechancetokeepthecarinlinebysteeringandbrakingaction.TheA-classisthefirstandonlycarinthesubcompactandcompactcarclasstohavesuchaninnovativedrivingsafetysystem.TheElectronicStabilityProgramalsoincludesthecompany’selectronicBrakeAssistSystem.8.2AdvancedFeaturesinFutureVehiclesThisisnotinthemanufacturer’sbestinterests.Somevehiclemanufacturersarevaliantlyattemptingtoimprovecustomersatisfactionatthedealerlevelandthistypeofeffortisbecomingmoreimportanttobrandloyaltyandperceptionsofdealerhonestyasaserviceprovider.Thetaskwillbecomeevermoreimportantinacomplexfuturesociety.EventhoughacentralregisterofallvehiclesmayprovideneededhistoricaldataforvariouspurposesandpermitquickInternetandfaxcontactwiththevehicleowner,thedealer’spersonalcontactwiththecustomerwillremainakeyingredientforoptimumriskreduction.Therearemanylocalissuesthatcouldaffectthedesignoffuturevehicles.Forexample,wheretherearemanyattachedorintegralgarages,shouldthehomebemodifiedorshouldthevehiclesbedesignedtominimizefuelvapor(evaporative)emissionsandexhaustemissions?Theconcerniswiththehealtheffectsofvolatileorganiccompoundsingeneral,benzeneinparticular,andcarbonmonoxide.ArecentstudyofMannindicatedthathomeswithattachedorintegralgarageshadbenzenelevelsthatgrosslyexceededtheapplicablestandards.Inonecase,thebenzeneinaroomabovethegaragewas2.5timestheambientstandard.BenzeneisaGroup1carcinogen(InternationalAgencyforResearchonCancer).Arelatedissueistherequestsbylocalgovernmentagenciestodesignautomobileexhaustsystemstobesuicide-resistantortoeliminatecarbonmonoxideemissions.Theambientairpollutionissuesarealsolocalincharacter,butupto70%oftheambient(environmental)benzeneemissionshavebeenattributedtoroadvehicles.Whatmayseemtobeaminorconstellationoflocalissuestodaymaybecomemuchmoreinthefutureandrequiresomeformofremedy.Mann的最近的一项研究表明，有附带车库和整体车库的房屋的苯含量严重超出了适用的标准。在一个案例中，车库上部的房屋内的苯是环境标准的2.5倍。苯是一种致癌物质(国际癌症研究机构)。一个相关问题是由当地政府机构要求设计汽车排气系统来消除自杀性和减少一氧化碳的排放。周围的空气污染问题也是具地域性的，但高达70%的环境苯排放来源于公路车辆。8.2.1StylingandAerodynamicsStylingchangesinfuturevehiclesareinevitabletoestablishbrandidentityanddemographicsalesappeal.Theaerodynamicconcerns,importantforfuelefficiencyratings,includeswirlingandrotatingvortices,periodicandunsteadyflows,andrelativelyincompressibleairflows.Bothstylingandaerodynamicsdirectlyaffectsafety.Sheetmetalstylingandtheattachedstructuresaffectcrashandcontrolledcrush.Aerodynamics,suchassmoothingoftheundersideofvehicles,couldbeintheformofdamage-resistantshields.However,potentialfuturevehiclesafetyproblemsmayarisefromthetendencytomakelast-minutestylingchangesandeliminateshieldingandskidplatesonacostandsimplicitybasis.Lightweightaluminumspaceframesandbodysegmentswithweldedstampedmetal,extrusions,andcastmaterialhavecrushandenergymanagementcharacteristicsdifferentfromconventionalsteelframes,structures,andbodypanels.Topreventproblems,thiswillrequireconventionaltestingandtime-testedexperience,becauseoftheintrinsicvariationsintheconfigurationsofspaceframes.未来的汽车样式的变化对于建立品牌标识和人口销售吸引力是不可避免的。空气动力学问题，重要的燃料效率评级，包括旋转涡流、周期性和不稳定的气流和相对不可压缩所引起的气流。汽车样式和空气动力学都会直接影响安全性。板金样式和附加的结构影响碰撞和受控制的压碎。空气动力学，如平滑车辆的底面，可表现为防破坏盾牌。8.2.2Four-wheelSteeringFour-wheelsteeringsystemsinpassengervehiclesandintrucksmayimprovelow-speedmaneuverability,butwillaffectdrivability.Thesesystemsaregenerallyrear-wheelsteeringsystemsintendedtosupplementthefront-wheelsteeringsystem.Atlowspeedstherearwheelsmoveinadirectionoppositetothatofthefrontwheels.Butathigherspeedstherearwheelsturninthesamedirectionasthefrontwheels.Thismayimprovevehiclestabilityathigherspeedsbyreducingvehicleyaw(rotationalmovement)duringlanechangingpassing,orevasiveactions.Itmayimprovetruckstabilitybyreducingcorrectivesteeringinwindgustsandtrailersway.Atlowspeedsforcarsandtrucks,itshortenstheturningradius.Theremaybehumanproblemsifthedrivercanmakeadjustmenttotherear-wheelsteeringatwill,bycontrolsontheinstrumentpanel.Drivabilityisinfluencedbydegreeofsteeringresponse,thedifferencebetweenneutralandactiverear-wheelsteering,thecharacteristicsofaparticularmodelvehiclecombinedwithitsloadandattachedtrailers,theexternalenvironmentalconditions(ice,snow,rain,windgustsandgrade)andthesophisticationofthedriver.8.2.3DisplayIntegrationThereisalreadyacapabilityofcombiningorintegratingmanydisplaysandcontrolsintoasingleliquidcrystaldisplayofalargeorsmallsize.Asingledisplaysavesspaceandthecostsofdiscretecomponents.Butintermsofthehumandriver,toomanyfunctionscouldaddcomplexity,confusion,andtoomanychoices.

Whatisimportantenoughtodisplay:temperaturecontrol,audiocontrol,time,interiorlighting,speed,fuellevel,theodometer,theestimatedtimeofarrival,hotelinformation,navigationaids,orotherfunctionsandinformation.Whatfunctionsshouldbesharedonthedisplay,suchasonasplitscreen,anoverride,orapermanentoverlay?Shouldanimproperphysicaldistancebetweenanoccupantandtheairbagcontrolunitorinstrumentpanelbedisplayeduntilcorrectedorshouldtheairbagdeploymentuntilitselfmakeanadjustment?Ifanimproperheadpositionisdetectedshouldithavedisplaypriority?Therearemanyquestionsandpossibledesignvariationswhichcouldaffectvehiclesafety.重要的应该被显示信息有:温度控制、音频控制、时间、室内照明、速度、燃料等级、里程表，预计到达时间，酒店信息、导航、或其他功能。应该在显示器上进行信息共享的功能，比如在分割屏幕，一个功能超越或一个永久覆盖？不适当在乘员和安全气囊控制单元或仪表板的物理距离应该被显示直到纠正？或安全气囊被展开直到本身作了调整？如果检测到不适当的头部位置，是否应该显示优先级?有许多的问题和可能的设计变化可能影响车辆安全。8.2.4AdaptiveHeadlightsSmartheadlights,intelligentadaptivefrontlightingsystems,orenhancedlightingsystemsprovideobvioussafetybenefits.Theymayswivelbylinkingsteeringdirectionwithheadlightbeamdirection,haveself-levelingheadlightsifnecessary,mayadjustthepatternofheadlightilluminationontheroadwayintermsofbeamdistance,width,scatter,andsymmetry.TheEuropeanasymmetric‘dippedbeam’lightpattern,providingilluminationtowardtheouteredgeoftheroad,maybechangedtoadaptivesymmetricallightingandstillmeettheregulatoryintentbymeanssuchascutoffsthatlimitthebeampattern.Theremaybebendinglights,eitherbyswivelingturningoneormoreheadlightsorbyincreasingthebrightnessofoneoftheheadlights.Theremaybeweatherlightsthatadjusttofog,rain,snow,orwetroads.Theremaybecitylightsthattakeintoconsiderationthepartialilluminationthatalreadyexistsandthelowspeedofthevehiclesinanurbanarea.Theremaybehighwaylightingwithagreaterbeampatterndistanceandacutofftoreduceglareordazzlet