Page 1 April 8, 2011 Cellar Conference 2011 Thomas Seder, PhD Human Machine Interface General Motors Global R&D April 8, 2011 Vehicle Cockpit Design that

Page 1April 8, 2011 Cellar Conference 2011

Thomas Seder, PhDHuman Machine Interface

General Motors Global R&D

April 8, 2011

Vehicle Cockpit Design that Accommodates

Human Age-Related Performance Depreciation


• Describe research motivation, goals & approach

• Present a framework for indentifying addressable issues

• Provide an overview of age-related performance depreciation issues

• Discuss our design philosophy and a set machine interface design guidelines

• Present a concept vehicle HMI that accommodates age-related human performance depreciation

Outline

aged driver interface visionaccommodative prescriptive therapeutic


MotivationDelay driving cessation to maintain quality of

life

71.5 Million, 20% of Population

• 65+ yr highly represented & growing fraction of population

• Crashes/ mile driven increases at ~age 65• Quality of life diminishes when ‘keys are taken

away’ • Reduced socialization depression• Missed Dr visits & reduced exercise health decline• Lost sense of freedom loss that was represented by

mobility

Number of people 65+ over time Crashes per mile by driver age all crashes per million miles travelled fatal crashes per 100 million miles travelled

37.3 Million, 12.4% of Population


Approach

Improve Situation Awareness

• Ability to act upon the world improves as world awareness increases

• Situation Awareness (SA) has numerous dependencies

User’s Mental Model of the World

Current State of the World

Situation Awareness

Perf

orm

an

ce

Perceive, Comprehend, Project


Framework for Issue IdentificationWicken’s Information Processing Model

Sensory Memory

PerceptionResponseExecution

feedbackSenses

Attention Resources

Decision Making

Working MemoryLong Term Memory

ResponseSelection

there’s a grand conspiracy of depreciations that robs the IP of the elderly, impacting their ability to

attain and maintain situation awareness

perceive, comprehend, respond


Depreciations, Impacts & Guidelines

age-related change impact general cockpit design guidelinevisual

1difficulties with accommodation (presbyopia) & dynamic accommodation - loss of flexibility & thickening of lens

inability to focus on close items and change focus quickly leading to longer glance duration and greater head down time

create high and forward displays, use easy to understand icons vs text, select large familiar font, increase contrast ratio, use expected words

2

reduced contrast sensitivity and spatial contrast sensitivity - due to signal lowering ( lower max diameter of iris, reduction in receptors, disorganization of receptors and reduced transmission of transparent structures) and noise floor increasing (opacity induced light scattering imparts veiling luminance washing over retina) and directionality of retinal receptor molecules become disorganized & responsive to off-axis light)

diminished acuity & dynamic acuity (fine detail resolution) creating difficulties in reading road signs, on-board displays and detail on moving objects; overall discrimability diminished particulalry at low ambient light levels

increase font x-height, font luminance and overall display CR, minimize in-cab reading, minimize diffuse reflection via display optical design and use of shrouding & material selection, minimize off axis light scattered off of vehicle surfaces into the ERP by material selection/ design (BDRF)

3

UFOV narrowing via deskilling-induced reduction in visual processing (reduced synaptic weight of unexercised connections), relative inefficient peripheral vision due to factors that contributed to reduced contrast sensitivity

missed cues in peripheral field; place or move important information in primary viewing envelope; simplify interface to avoid cognitive tunneling

4

reduction in perceivable color space - free radical-induced molecular crosslinking creating blue absorbing moieties (yellow) normally transparent structures

change in color space perception - notably blue sensitivity and reduced color discrimination

avoid use of blue (particualrly saturated) and cyan chromaticities, execpt for filled area background; avoid saturated colors in large area fills, leverage population stereotypes

5

glare sensitivity - free radical-induced molecular crosslinking of cristallin creating accumulation of scattering centers (cataracts) in the lens, cell death (thinning) & alignment reduces pigment epithelium OD post retina allowing backscattering of light; all coupled with hypersensitive cones if unstimulated as in night vision

sensitivity to intense lights off axis sources, specular reflections

squelch specular reflections through use of AR technologies or manage direction away from ERP, select diffuse reflection materials for trim features; enable use of eley worn polarizers to block Brewster's angle reflections by providing high lumiance displays emitting circular polarized light

8glare induced photo-bleaching of rods in the dark adapted and longer recovery from photo-bleaching

bright sources cause a distracting and enduring disruption to normal perception

squelch specular reflections by material selection and through use of AR technologies, all mirrors should autodim

9 reduced vitreous humor viscosity increasing particle mobility appearance of distracting floaters ----

10mechanical excitation of retinal structures due to posterior detachment of vitreous humor

light flashes ----

12 increased saccadic latency and velocity, slower pursuit velocities greater time required to locate an object in a visual fielddramatically declutter instrument panel and learn to abhor animations

13

reduced depth perception (BU processes) - due to accommodation difficulties, binocular disparity decline and decline of the proprioceptive convergence signal

poor distance judging, rate of closure estimation


Depreciations, Impacts & Guidelines

age-related change impact general cockpit design guidelineaural

1

sensorineural hearing depreciation ( tinnitus (12% on men 65+) & presbycusis) - notably higher detection threshold and loss of detection of higher frequencies (>400Hz)

higher detection threshold, diminished ability to locate location of sound source, missed audible cues

avoid cues > 4000 Hz, use male voices for synthetic voices, allow user volume control, use redundant channel, i.e., visual

haptic

1

reduced touch sensitivity - relatively greater depreciation of Pacinian corpuscle (thickening), relative to Ruffini endings, Meissner corpuscles & Merkel disks

diminishing high frequency detection use low frequency alerts (~25 Hz)

cognititive

1 decreased working memory capacity and persistence inability to hold and process information for decision making

devise intuitive, easily understood displays that match users mental model (metaphoric); allow the vehicle to maintain lists - 'put knowledge in the world and not in the head'; employ functional grouping of information and automation when possible,

2reduced retrieval rates from semantic long term memory, even though information persists

can lead to delay in cognitive processes that rely on LTM, such as decision making, perception and ultimately action

leverage the asset of LTM

3 weakened prospective LTM - forgetting to do something in the future task omission provide checklists and other memory aids

4ingrained procedural memory (automaticity) causes an inability to lean new procedures

prior procedural learnings appear, particularly when stressed don't demand changing of strong mental models

5slower attention resources & diminished divided attention , reduced selective attention capability and slower dynamic visual attention

search tasks are slower, scanning is reduced and the UFOV narrows, weaker ability to simultaneously perform two attention requiring tasks

place or move important information in primary viewing envelope; simplify interface- develop UFOV training interface (?)

6focused attention is weakened, particularly in the presence of salient distracters

overly responsive to flashing lights, loud sounds and conspicuous iconsavoid clutter, avoid salient alerts, avoid whizzy start up shows and screen transitions

7

information processing is weaker due to the grand conspiracy of weakened inputs (sensory) limited attention resources, which affects perception, lower capacity WM and slower LTM

error prone decisions, missed cues, slow responses, anxiety, frustration

provide a clean, aestheticall pleasing design having inportant and frequently needed information in the PVE, use redundancy and technology to assist when necessary (e.g., blind spot detection)

other1 mild cognitive impairment in 20% of 65+ additional cognition depreciation

2 fragmented sleep causes fatigue in waking hoursdrowsiness and lack of alertness taxes cognition; revealed as decreased response time, indecisiveness, anxiousness & lost confidence and overall loss of situation awareness

3increased prevalence of medical conditions such as diabetes (retinopathy) and macular degeneration (wet & dry)

retinal detachment, undernourishment of retina and clouded vision / central vision loss

4 arthritis and muscle mass lossstrength & range of motion diminished, rate of movement slowed, loss of fine motor skill


Display guidelines:• Leverage avionics architectures & info management

schema– Design for the copilot– Create an extended mind– Put knowledge in the world

• Provide an architecture that affords easy information access– Physical location based on criticality, frequency of

use and matched to user viewing envelope– Employ functional grouping– Provide redundant communication – Eliminate distracting, low information content items

• Use size, color, luminance and location to communicate relative importance

• Limit color palette to 4 or 5 meaningful colors; consistent usage

Design Philosophy & Additional Design Guidelines

‘quiet & uncluttered | intuitive & accommodating’


Controls guidelines:• Design controls that exhibit metaphoric movements • Avoid fine motor skill movements

Interaction & industrial design guidelines:• Leverage aesthetic-usability coupling• Provide consistent interaction design throughout

cockpit• Design in monochrome first & use color for

redundancy

Design Philosophy & Additional Design Guidelines

‘quiet & uncluttered | intuitive & accommodating’


• Proper selection of display technology– LCD with LED backlight (or OLED)– High maximum ERP luminance (1000 cd/m2)– Low black state ERP luminance (2 cd/m2)– Low diffuse reflectance in 6000 fC high

ambient enables abundant contrast

low ambient ERP contrast > 500:1high ambient ERP contrast >15:1

• Include bezel mounted ambient irradiance sensors for automation dimming along with master dimmer for luminance customization

Technology SelectionPrimary & Secondary Displays


• Select wide color space with saturated green (555 nm) & red

• Balance luminance to favor V stimulation

• Communicate importance hierarchy via gray level luminance

Technology Selection Primary & Secondary Displays

Color u' v' % of whitewhite 100green 0.125 0.562 70red 0.441 0.525 25blue 0.178 0.224 5

display item color u' v' luminance typefacespeed characters white 0.222 0.484 100 Frutiger, 1-1/ 2"speed ring gray 0.222 0.484 2PRND white 0.222 0.484 100 Frutiger, 1-1/ 2"turn indicator (0-15 sec) green 0.125 0.562 40turn indicator (> 60 sec, moving) green 0.125 0.562 60blind spot hazard amber 0.264 0.542 20blind spot warning red 0.441 0.525 25telltale check engine characters amber 0.264 0.542 20 Frutiger' 3/ 4"telltale check engine icon amber 0.264 0.542 20telltale low fuel characters amber 0.264 0.542 20 Frutiger' 3/ 4"telltale low fuel icon amber 0.264 0.542 20telltale low fuel characters amber 0.264 0.542 20 Frutiger' 3/ 4"telltale low fuel icon red 0.441 0.525 25telltale seat belt icon amber 0.264 0.542 20


System Overview3 Display Architecture


• massively decluttered

• speed indicator at 100% grayscale for CRmax & chromaticity chosen for max E*

• font height and weight selected to assure visibility• Media appropriate, familiar typeface to assure readability -

Frutiger• for harmony & minimal distraction, the ring

– acts to center and ground speed indicator– GS luminance set 1% of indicator and – at same chromaticity

• aesthetically pleasing universal design

Primary Display - Piloting


Primary Display - Piloting

amber when turn indicator onredundant with side view mirror

indicator

red when car deviates toward collision

couples with audible & haptic alerts

low fuel: amberextremely low fuel: redPRND replaces speed at 0 mph

large directional indicatorsluminance increase after 60 s

safety & walk-home telltales directional indicators

blind spot hazard indicator collision warning indicator


• Functional grouping of information with defined areas• Simple fuel gauge with range & odometer displays

persistently• Gauge labels, range & odo mile labels appear and

remain on screen until user shifts into drive

Head Down Driver Navigation & Information Display


• Navigation system based on MOVE (Hudson & Forlizzi, CMU)

• Based on UCD techniques, focusing on features of hand drawn maps

• Uses abstraction techniques that reduce clutter and match user’s mental model of navigation process– Semantic information rich labeling at major maneuvers– Less salient symbolic labeling prior to next maneuver– Displays only salient navigation landmarks – traffic lights, bridges

Head Down Driver Navigation & Information Display

# glances by 3Xglance dwell time by 6Xlane keeping by 5X

Simulator TestingMOVE vs Linedrive


Future Work

• Continued refinement and development of design guidelines

• Building a non-drivable aesthetic property for qualitative user assessment of basic design

• Build design into reconfigurable cockpit to enable quantitative user performance testing and iterative design refinement

• Enrich design by evaluating persuasive prompts

• Evaluate and address deskilling that may appear if interface is unchallenging

Documents

Page 1 April 8, 2011 Cellar Conference 2011 Thomas Seder, PhD Human Machine Interface General Motors Global R&D April 8, 2011 Vehicle Cockpit Design that