chris schwarz, ph.d. 9/1/2016 transfer from highly...
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ChrisSchwarz,Ph.D. 9/1/2016
TransferfromHighlyAutomatedtoManualControlPerformance&Trust
Adrivingsimulatorstudywasperformedwith20participantstostudytransfersofcontrolinhighlyautomatedvehicles.Weobserveddriverperformanceandmeasuredcomfortasanindicatorofthedevelopmentoftrustinthesystem.Onescenariousedanautomationsystemthatwasabletorespondtomosteventsbyslowingorchanging
lanesonitsown.Theotherstudydriveissuedtakeoverrequests(TORs)inallcases.Thustherewasachangeinreliabilityoverthecourseofthestudydrives,wheresomeparticipantsexperiencedthemore-capable
systemfirstandotherstheless-capable.
Studyeventsincludedaworkzone,asectionwithmissinglanelines,anelevatedrampcurve,aslowleadvehicle,andanexitrampasthefinalevent.Extraeventswithleadvehiclesthatchangedspeedservedasexamplesofsuccessfulautomationinterventions.
Atriviataskfromwww.triviaplaza.comwasusedtoengagetheoperatorwhileinautomatedmode.Ratherthanbeingasecondarytask,thiswastheprimarytaskduringperiodsofautomation.
ExperimentalSetup
Automated-modeiconandimminenttakeoverrequest
NADS-1motionbase
LongitudinalmeasuresLongitudinalMeasuresComfortMinimumspeedMeanspeedSteeringreversalrateStd.dev.lanepositionHigh-frequencysteeringPercentroadcentergaze
Transferofcontrolexampleswithvariedexpectation Expected UnexpectedLowertoHigher Buttonpress CollisionavoidanceHighertoLower Grabwheel Automationfailure
ChrisSchwarz,Ph.D.
TakeoverrequestsweremodeledaftertheinterfacesusedinrecentNHTSAresearchonlevel2/3automation(Blancoetal.,2015).
Weobservedthreetypesofpeoplewithrespecttotheircomfortprofilesoverthecourseoftheirthreedrives.Somestartedoutverycomfortable,otherstookalongtimetobecomecomfortable,andothersincreasedincomfortfairlyquickly.
Takeoversweresplitintophysicaltakeover,visualattention,andvehiclestabilization.Wedidnotattempttoquantifythetimerequiredtoregainfullsituationalawareness.Driverswereabletophysicallytakecontrollessthanfivesecondsafterbeingrequestedto.However,responsetimeandperformancemeasuresshowedthattherewasa15-to25-secondperiodbetweenthephysicaltakeoverandareturntonormaldrivingperformance.Thisconfirmssomeobservationsinpreviousstudiesontransferofcontrol(Goldetal.,2013;Meratetal.,2014).
NoothereventexposeddifferencesbetweenthestudygroupsaswellastheslowleadvehicleeventinDriveB.Womenwereseentoachievelowerminimumspeedsthanmen.Menspentmoretimeinmanualmodethandid
women.YoungerdrivershadalowerSRRandlargerSDLPthandidtheoldergroup.Finally,whendriversexperiencedthiseventintheirfirstdrive,theytendedtohavelargeramountsofhigh-frequencysteeringthanwhentheyexperienceditintheirseconddrive.
References
Blanco,M.,Atwood,J.,Vasquez,H.M.,Trimble,T.E.,Fitchett,V.L.,Radlbeck,J.,Fitch,G.M.etal.(2015).HumanFactorsEvaluationofLevel2andLevel3AutomatedDrivingConcepts.FinalReportDOTHS812182.Washington,D.C.:NHTSA.
Gold,C.,Damböck,D.,Lorenz,L.,&Bengler,K.(2013).‘Takeover!’Howlongdoesittaketogetthedriverbackintotheloop?”ProceedingsoftheHumanFactorsandErgonomicsSocietyAnnualMeeting57(1):1938–42.
Merat,N.,Jamson,A.H.,Lai,F.C.H.,Daly,M.,&Carsten,O.M.J.(2014).Transitiontomanual:Driverbehaviourwhenresumingcontrolfromahighlyautomatedvehicle.TransportationResearchPartF:TrafficPsychologyandBehaviour.
“Thereisa15-to25-secondgapbetweenphysicaltakeoverandvisualattention/stabilizationduringwhichthedrivermaybevulnerabletomissingasafety-criticaleventataninopportunemoment.”