无人驾驶汽车

Anautonomousvehicleisanautomobilethathasanautopilotsystemallowingittosafelymovefromoneplacetoanotherwithouthelpfromahumandriver.[]Insomeotherpassages,itisalsoknownasdriverlessvehicle,orself-drivingvehicle,orroboticvehicle.AutonomousvehiclesdetectsurroundingsusingAI(ArtificialIntelligence),radar,lidar,GPS,Odometry,andcomputervision.Artificialintelligenceistheintelligenceexhibitedbymachinesorsoftware.[]Artificialintelligencebasedonthesense/plan/actagentstructureisappliedtotheautonomousvehicles.Itcansimulatehumandrivingbehaviorfromthreelevelsofsense,thinkingandbehavior.[]Aradarisanobject-detectionsystemthatusesradiowavestodeterminetherange,angle,orvelocityofobjects.Aradartransmitsradiowavesormicrowavesthatreflectfromanyobjectsintheirpath.Areceiveradar,whichistypicallythesamesystemasthetransmitradar,receivesandprocessesthesereflectedwavestodeterminepropertiesoftheobject(s).Lidarisasurveyingtechnologythatmeasuresdistancebyilluminatingatargetwithalaserlight.LidarexistsasanacronymofLightDetectionAndRanging,andwasoriginallycreatedasaportmanteauoflightandradar.TheGlobalPositioningSystemisaspace-basednavigationsystemthatprovideslocationandtimeinformationinallweatherconditions,anywhereonorneartheEarth.Odometryistheuseofdatafrommotionsensorstoestimatechangeinpositionovertime.Odometryisusedbysomerobotstoestimatetheirpositionrelativetoastartinglocation.Computervisionisafieldthatincludesmethodsforacquiring,processing,analyzing,andunderstandingimagesand,ingeneral,high-dimensionaldatafromtherealworld.Anewmethodbasedoncomputervisioncanreconstructtheroadsurfacefromtheimages.Itcansolvetheshortcomingsthattheimageofthefarlaneistoosmallanddifficulttodetect.Advancedcontrolsystemsinterpretsensorinformationtoidentifyappropriatenavigationpaths,obstaclesandrelevantsignage.Autonomousvehicleshavecontrolsystemsthatarecapableofanalyzingsensordatatodistinguishdifferentcarsontheroad,whichareveryusefulinplanningapathtothedesireddestination.Somedemonstrativesystems,precursorytoautonomousvehicles,datebackto1920s.Thefirstself-sufficientcars,trulyautonomous,appearedinthe1980s.Sincethen,numerousmajorcompaniesandresearchorganizationshavedevelopedautonomousvehicles.[]InChina,researchesaboutautonomousvehiclesoccurredin1980s,andthefirstautonomouscarwassuccessfullydevelopedbyNationalUniversityofDefenseTechnologyin1992.[]Actually,autonomousisbasedonsomefundamentalsystems.Autonomouscruisecontrol,alsocalledasadaptivecruisecontrolisanoptionalcruisecontrolsystemforroadvehiclesthatautomaticallyadjuststhevehiclespeedtomaintainasafedistancefromvehiclesahead.Itmakesnouseofsatelliteorroadsideinfrastructuresnorofanycooperativesupportfromothervehicles.Hencecontrolisimposedbasedonsensorinformation.CooperativeAdaptiveCruiseControl(CACC)furtherextendstheautomationofnavigationbyusinginformationgatheredfromfixedinfrastructuresuchassatellitesandroadsidebeacons,ormobileinfrastructuresuchasreflectorsortransmittersonthebackofothervehicles.Automaticparkingisanautonomouscar-maneuveringsystemthatmovesavehiclefromatrafficlaneintoaparkingspottoperformparallel,perpendicularorangleparking.Theautomaticparkingsystemaimstoenhancethecomfortandsafetyofdrivinginconstrainedenvironmentswheremuchattentionandexperienceisrequiredtosteerthecar.Electronicstabilitycontrol(ESC),alsoreferredtoaselectronicstabilityprogram(ESP),isacomputerizedtechnologythatimprovesavehicle'sstabilitybydetectingandreducingskidding.[]WhenESCdetectslossofsteeringcontrol,itautomaticallyappliesthebrakestohelpsteeringthevehiclewherethedriverintendstogo.Lanedeparturewarningsystemisamechanismdesignedtowarnthedriverwhenthevehiclebeginstomoveoutofitslane.Therearetwomaintypesofthesystem,oneofwhichwarnsthedriverifthevehicleisleavingitslane.Theotherwarnsthedriverorautomaticallytakesstepstoensurethevehiclestaysinitslaneifnoactionistaken,whichmaybeappliedtoautonomousvehicles.Collisionavoidancesystem,alsoknownaspre-crashsystem，isanautomobilesafetysystemdesignedtoreducetheseverityofacollision.Itdetectsanimminentcrashbyusingradarinweatherconditions,andsometimesusinglidarandcamerawhichareineffectiveinbadweather.Automatedhighwaysystem,alsoknownasSmartRoadisaproposedintelligenttransportationsystemdesignedtoprovideforautonomousvehiclesonspecificway.Itisoftenrecommendedasameansofrelievingtrafficcongestion,onthegroundsthatitwoulddrasticallyreducefollowingdistancesandheadway,thusallowingagivenstretchofroadtocarrymorecars.Withthedevelopmentofautonomousvehicletechnology,numerousmajorcompaniesandresearchorganizationshavedevelopedworkingprototypeofautonomousvehicles,includingMercedes-Benz,GeneralMotors,ContinentalAutomotiveSystems,IAV,GoogleandBaidu,ect.Someexpertspredictthatthevehicledrivingwillexperiencefourstepsincludingauxiliarydriving,semi-autonomousdriving,highlyautonomousandfullyautonomousdriving.Mostofthesecompanieshavemadegreatprogressinautonomousvehicletechnology.Mercedes'6dsystemhasbeenappliedtothecompany'shigh-endcars.Thestereovisionsystemcannotonlyfindobstacles,butalsoidentifywhattheobstaclesare.Itcandiscoverandidentifypedestria