The Role of Motion Cues in The Role of Motion Cues in Simulation TestingSimulation Testing

Gregory DavisFHWA Office of Safety RD&T

FHWA Highway Driving FHWA Highway Driving SimulatorSimulator

Saturn SL1 Car Saturn SL1 Car CabCab

240 Degree 240 Degree Cylindrical Cylindrical Projection Projection ScreenScreen

3-DOF 3-DOF Electrical Servo Electrical Servo Motion BaseMotion Base

HDS UpgradeHDS Upgrade Current Upgrade of System Hardware Current Upgrade of System Hardware

and Software is in Progressand Software is in Progress SGI Onyx Infinite Reality has been SGI Onyx Infinite Reality has been

replaced with Dell PCsreplaced with Dell PCs One ElectroHome Projector replaced One ElectroHome Projector replaced

with 3 Barco Projectorswith 3 Barco Projectors Complete upgrade will total 5 Barcos Complete upgrade will total 5 Barcos

for 240 Degree Field of View (’05) for 240 Degree Field of View (’05)

Computer HardwareComputer Hardware 5 Dell 5 Dell

workstations will workstations will be used to drive be used to drive each projectoreach projector

Dell PCs use Dell PCs use Quadro NVIDIA Quadro NVIDIA FX 3000G FX 3000G Graphics CardsGraphics Cards

Low Cost with Low Cost with High Frame RateHigh Frame Rate

ProjectorsProjectors 3 Barco 909 3 Barco 909

Projectors now in Projectors now in placeplace

Mounted above Car Mounted above Car Cab on Circular Cab on Circular Gantry FrameGantry Frame

Ability to deliver Ability to deliver 2048 x 1536 2048 x 1536 ResolutionResolution

Motion BaseMotion Base 3 Electrical Servo 3 Electrical Servo

MotorsMotors Capable of Pitch, Capable of Pitch,

Roll, and HeaveRoll, and Heave +/- 8 degrees for +/- 8 degrees for

Pitch and Roll Pitch and Roll each, 5 degrees each, 5 degrees combinedcombined

Heave 2.5 inches Heave 2.5 inches at about 2-3 hzat about 2-3 hz

Crossbow Inertia Crossbow Inertia GyroscopeGyroscope

Vehicle Dynamics ModelVehicle Dynamics Model 6 DOF Equations (although capable of only 3)6 DOF Equations (although capable of only 3) Simplified model of 4 speed Auto Simplified model of 4 speed Auto

TransmissionTransmission Tire Skid Limits on side force and braking Tire Skid Limits on side force and braking

forceforce Steering wheel disturbances (force feedback)Steering wheel disturbances (force feedback) Motion Base ControlMotion Base Control Roadway Surface ConditionsRoadway Surface Conditions

Issues and Questions?Issues and Questions?Which types of experiments require Which types of experiments require

motion based cues?motion based cues? Studies on Braking? Reaction Studies on Braking? Reaction

Time=maybe not. Brake force=yes.Time=maybe not. Brake force=yes. Studies on lane keeping-speed = yesStudies on lane keeping-speed = yes Studies on roadway design or sign Studies on roadway design or sign

comprehension = maybe, depends comprehension = maybe, depends on experimental designon experimental design

If motion cues are required, how much If motion cues are required, how much motion is needed to achieve the desired motion is needed to achieve the desired effect?effect?

Which method of motion is more conducive Which method of motion is more conducive to achieving accurate and reliable results in to achieving accurate and reliable results in a simulator, the traditional method or the a simulator, the traditional method or the vector substitution method? (e.g. tilting the vector substitution method? (e.g. tilting the car cab down {traditional} or up {vector car cab down {traditional} or up {vector substitution} during vehicle brakingsubstitution} during vehicle braking

Does the appropriate motion contribute to Does the appropriate motion contribute to or mitigate motion sickness?or mitigate motion sickness?

……And More Questions?And More Questions?

FinallyFinally

Do we need standards for motion Do we need standards for motion cues?cues?

AcknowledgementsAcknowledgementsSpecial Thanks to:Special Thanks to:

Jason Williams (AAI Eng.)Jason Williams (AAI Eng.)John Molino (SAIC)John Molino (SAIC)