Junior：The-Stanford-Entry-in-the-Urban-Challenge

Junior:TheStanfordEntryintheUrbanChallengeMichaelMontemerlo1,JanBecker4,SuhridBhat2,HendrikDahlkamp1,DmitriDolgov1,ScottEttinger3,DirkHaehnel1,TimHilden2,GabeHoffmann1,BurkhardHuhnke2,DougJohnston1,StefanKlumpp2,DirkLanger2,AnthonyLevandowski1,JesseLevinson1,JulienMarcil2,DavidOrenstein1,JohannesPaefgen1,IsaacPenny1,AnnaPetrovskaya1,MikePflueger2,GanymedStanek2,DavidStavens1,AntoneVogt1,andSebastianThrun11StanfordArtificialIntelligenceLab,StanfordUniversity,StanfordCS943052ElectronicsResearchLab,VolkswagenofAmerica,4009MirandaAvenue,PaloAlto,CA943043IntelResearch,2200MissionCollegeBlvd.,SantaClara,CA950524RobertBoschLLC,ResearchandTechnologyCenter,4009MirandaAvenue,PaloAlto,CA94304Abstract.ThisarticlepresentsthearchitectureofJunior,aroboticvehiclecapableofnav-igatingurbanenvironmentsautonomously.Indoingso,thevehicleisabletoselectitsownroutes,perceiveandinteractwithothertraffic,andexecutevariousurbandrivingskillsinclud-inglanechanges,U-turns,parking,andmergingintomovingtraffic.ThevehiclesuccessfullyfinishedandwonsecondplaceintheDARPAUrbanChallenge,arobotcompetitionorga-nizedbytheU.S.Government.1IntroductionThevisionofself-drivingcarspromisestobringfundamentalchangetooneofthemostessentialaspectsofourdailylives.IntheU.S.alone,traf-ficaccidentscausethelossofover40,000peopleannually,andasubstan-tialfractionoftheworld’senergyisusedforpersonalcar-basedtransportation[U.S.DepartmentofTransportation,2005].Asafe,self-drivingcarwouldfunda-mentallyimprovethesafetyandcomfortofthedrivingpopulation,whilereducingtheenvironmentalimpactoftheautomobile.In2003,theDefenseAdvancedResearchProjectsAgency(DARPA)initiatedaseriesofcompetitionsaimedattherapidtechnologicaladvancementofautonomousvehiclecontrol.Thefirstsuchevent,the“DARPAGrandChallenge,”ledtothedevelopmentofvehiclesthatcouldconfidentlyfollowadeserttrailataverageve-locitiesnearing20mph[Buehleretal.,2006].InOctober2005,Stanford’srobot“Stanley”wonthischallengeandbecamethefirstrobottofinishthe131-milelongcourse[Montemerloetal.,2006].The“DARPAUrbanChallenge,”whichtookplaceonNovember3,2007,broughtaboutvehiclesthatcouldnavigateintrafficinamockurbanenvironment.TherulesoftheDARPAUrbanChallengewerecomplex[DARPA,2007].Ve-hicleswereprovidedwithadigitalstreetmapoftheenvironment,intheformofaRoadNetworkDescriptionFile,orRNDF.TheRNDFcontainedgeometricM.Buehleretal.(Eds.):TheDARPAUrbanChallenge,STAR56,pp.91–123.springerlink.comcSpringer-VerlagBerlinHeidelberg200992M.Montemerloetal.IBEOlaserDMIBOSCHRadarSICKLDLRSlaserVelodynelaserRiegllaserSICKLMSlaserApplanixINSFig.1.Junior,ourentryintheDARPAUrbanChallenge.Juniorisequippedwithfivedifferentlasermeasurementsystems,amulti-radarassembly,andamulti-signalinertialnavigationsystem,asshowninthisfigure.informationonlanes,lanemarkings,stopsigns,parkinglots,andspecialcheck-points.Teamswerealsoprovidedwithahigh-resolutionaerialimageofthearea,enablingthemtomanuallyenhancetheRNDFbeforetheevent.DuringtheUrbanChallengeevent,vehiclesweregivenmultiplemissions,definedassequencesofcheckpoints.Multipleroboticvehiclescarriedoutmissionsinthesameenviron-mentatthesametime,possiblywithdifferentspeedlimits.Whenencounteringan-othervehicle,eachrobothadtoobeytrafficrules.ManeuversthatwerespecificallyrequiredfortheUrbanChallengeincluded:passingparkedorslow-movingvehi-cles,precedencehandlingatintersectionswithmultiplestopsigns,mergingintofast-movingtraffic,leftturnsacrossoncomingtraffic,parkinginaparkinglot,andtheexecutionofU-turnsinsituationswherearoadiscompletelyblocked.Vehiclespeedsweregenerallylimitedto30mph,withlowerspeedlimitsinmanyplaces.DARPAadmittedelevenvehiclestothefinalevent,ofwhichthepresentvehiclewasone.“Junior,”therobotshowninFigure1,isamodified2006VolkswagenPassatWagon,equippedwithfivelaserrangefinders(manufacturedbyIBEO,Riegl,SICK,andVelodyne),anApplanixGPS-aidedinertialnavigationsystem,fiveBOSCHradars,twoIntelquadcorecomputersystems,andacustomdrive-by-wireinterfacedevelopedbyVolkswagen’sElectronicResearchLab.Thevehiclehasanobstacledetectionrangeofupto120meters,andreachesamaximumvelocityof30mph,themaximumspeedlimitaccordingtotheUrbanChallengerules.JuniormadeitsJunior:TheStanfordEntryintheUrbanChallenge93Fig.2.Allcomputingandpowerequipmentisplacedinthetrunkofthevehicle.TwoIntelquadcorecomputers(bottomright)runthebulkofallvehiclesoftware.Othermodulesinthetrunkrackincludeapowerserverforselectivelypoweringindividualvehiclecomponents,andvariousmodulesconcernedwithdrive-by-wireandGPSnavigation.A6DOFinertialmeasurementunitisalsomountedinthetrunkofthevehicle,neartherearaxle.drivingdecisionsthroughadistributedsoftwarepipelinethatintegratesperception,planning,andcontrol.Thissoftwareisthefocusofthepresentarticle.JuniorwasdevelopedbyateamofresearchersfromStanfordUniversity,Volk-swagen,anditsaffiliatedcorporatesponsors:Applanix,Google,Intel,MohrDavi-dowVentures,NXP,andRedBull.ThisteamwasmostlycomprisedoftheoriginalStanfordRacingTeam,whichdevelopedthewinningentry“Stanley”inthe2005DARPAGrandChallenge[Montemerloetal.,2006].IntheUrbanChallenge,Ju-niorplacedsecond,behindavehiclefromCarnegieMell