Design of Visual Displays for Driving Simulator Research

Design of Visual Displays for Driving Simulator Research

G. John Andersen

Department of Psychology

University of California, Riverside

Vision Issues in Driving Simulators

• Driving tasks require accurate perception of depth and distance in the 3D scene– What sources of information are critical– Integration of sources– Conflict between sources

• Visual Display – Display characteristics (Aliasing, Flicker,

Update,Refresh, Resolution)

Failure to Consider these issues in Driving Simulators

• Poor task performance• Low external validity of results• Poor transfer of training• Increased risk of simulator sickness

Driving tasks and Perception of Depth and Distance

, 96

Cutting, 1996

Depth

Con

trast

Depth (meters)

Occlusion

1 10 100

Size constancy

Cast Shadows

Disparity

Motionparallax

Convergence

Aerial

Overall scene depth

Layout of Objects

Properties of Objects

Viewer-centered

Information

Accommodation

Linear Perspective

Disparity

Motion Parallax

Linear Perspective

Relative Size

Motion Parallax

Texture (perspective)

Specular Highlights

Object-centered

Information

Surrounding Frame

Compression Gradient

Structure from Motion

Compression Gradient

Structure from Motion

Texture (non-perspective)

Shading

Andersen, Braunstein, & Saidpour, 1998

Driving Tasks and Perception

• Multiple sources of information available for driving tasks– What information is critical for what tasks

• Multiple sources for a specific task• Different tasks require different information

sources

– Use of multiple sources• Cue interactions• Cue conflicts

Multiple sources for a specific task: Collision Detection

• Model based on analysis of visual information available to driver (Andersen & Sauer, 2004)– Use of 5 parameters

motion parallax; optic flow)

d/dt (motion parallax; optic flow)

d/dt

ds (texture gradients, disparity, relative size)

Front View Top View

t=1

t=0

specifies the time to contact during constant velocitycollisions

a is the bearing of an object relative to a reference

ddt, dsd/dt, d/dt,

ddt, ds

ddt, ds

d/dt, d/dt, ddt, ds

ddtds ddt, ds

ddt, ds

d/dt, ds

ddt

d/dt, ddt, ds

d/dt, d/dt, d/dt, ds ddt

d/dt

d/dt, ddt, ds

d/dt, ddt, ds

d/dt, ddt, ds

d/dt, ddt, ds

d/dt, ddt, ds

d/dt, ddt, ds

Vehicle Motion

ObjectMotion

F = Fixed Speed V = Variable SpeedS = Straight Path C = Curved Path

No

F/S

V/S

F/C

V/C

No F/S V/S F/C V/C

Is =0? Or d/dt0?(constant angular

direction)

Is >0?(expansion)?

Yes

No

Yes

Is d/dt =0?(Constant expansion)

No

Derive

d/dt

Is d/dt >=-0.5?

No

Collision Object

Derivedv-ds

Is dv-ds >0?

Yes

Non-collision Object

Derive

Derive d/dt(angular direction)

Is dv-ds =0?(Constant expansion)

No

Yes

SelectObject

Different tasks and different sources of information

Two tasks with different sources of information

- Collision Detection (constant speeds and linear trajectories): Optical Expansion (TTC) and

-Vehicle Speed: Edge Rate

Question: Does information from one task affect use of information for second task

Experiment• Issue: Does information for one

task affect use of information for a different task

• Task: collision detection

• Independent Variables– Collision or non-collision object

– Time to contact (TTC)

– Different combinations of vehicle speed and object speed

• Dependent variable– Sensitivity (d’)

Vehicle / Object Velocity

d'

2.4

2.6

2.8

3.0

3.2

3.4

3.6

3.8

4.0

4.2

4.4

4.6

0/-0.8 0.2/-0.6 0.4/-0.4 0.2/-0.6

TTC 3.5 s

TTC 4.5 s

TTC 5.5 s

Simulators depict a 3D world

Perception of 3D scene includes-Texture gradients-Motion parallax-Occlusion-other information sources

Visual system also has cues for perceiving the distance to the display

3 Information sources for depth and distance of Display

- Binocular Disparity

- Eye convergence

- Accommodation

, 96

Cutting, 1996

Depth

Con

trast

Depth (meters)

Occlusion

1 10 100

Size constancy

Cast Shadows

Disparity

Motionparallax

Convergence

AerialAccommodation

Visual Cue Conflicts between display cues and 3D scene cues

Visual Cue conflict:

- Disparity, convergence and accommodation information specify display is flat

- Motion parallax, texture gradients, and other cues specify scene is 3D

Human Factors Solutions to these Issues

• Determine perceptual information needed for driving tasks of interest

• Design displays to optimize performance of tasks– Consider interactions of different information sources

• Minimize cue conflicts• Design for optimal performance not for high

fidelity– Question need of high fidelity rendered scenes, control

dynamics and fixed/variable base simulator