theoretically guided hmi development for a driver assistance system

Theoretically guided HMI development for a driver assistance system

Anke SchwarzeTU Braunschweig | Department of Research Methods and Biopsychology

May 25th 2011 | Anke Schwarze | page 2

Overview

Principles of HMI-development classically designed HMIs behaviourally designed HMIs

VIDE principle scenarios

Assessment of VIDE subjective and objective data

Adaptation to a specific situation

Summary and outlook


Classically designed HMIs

presentation of information about the status of the vehicle information has to be perceived, processed, and an adequate reaction has to

be identified and executed

arbitrary stimulus-reaction-configurations are used the driver has to interpret the signal to produce the correct reaction

the information processing of the driver is manipulated

the use of many cognitive resources is necessary

http://www.bmw.com/at/de/insights/technology/technology_guide/articles/_shared/img/info_display.jpg http://www.maxxcount.de/maxxcount/CustomUpload/374O357O340O370O356O369O350O332O352O375O375O322O366O372O365O371O/Con_M_GATEWAY-CAN_FIS-Display2_gross.jpg http://www.bmw.com/at/de/insights/technology/technology_guide/articles/_shared/img/multi_information_display.jpg


Reducing the amount of information processing

Reduction of the necessary information processing of the driver if…

…behaviourally relevant information is presented

…pre-programmed and consolidated stimulus reaction configurations are used

…the behaviour of the driver is manipulated


Classical and behavioural approach

Classical approach

information about the status of the car

use of arbitrary stimulus-reaction configurations

manipulation of the information processing of the driver

communication

Behavioural approach

behaviourally relevant signals

use of pre-programmed and consolidated stimulus-reaction links

manipulation of the behaviour of the driver

coupling of behaviour


HMI development

Our „rational“ approach

general strategy of developing HMIs no substitution of cognitive systems

analysis of the situation, identification of theoptimal reaction

finding out how this reaction can be provokedlevels of behavioural control if a fast and simple reaction is necessary:

low level of behavioural control if a complex reaction is necessary and there

is no time pressure: high level of behaviouralcontrol

levels of behaviouralcontrol (Eggert, 2007)

insight

instructions

models

operant conditioning

classical conditioning

imprinting

instincts

reflexes

com

plex

ityst

abili

ty


Three core questions in the design of ADAS

What does the behavioural repertoire of the driver consist of?

Which situation-specific reaction should be elicited?

How can the desired reaction be elicited most efficiently?


APPLYING THE APPROACH IN THEDESIGN OF A DRIVINGASSISTANCE SYSTEM


The assistance system – characteristics

the assistance system should assist the driver during his normal drivingtask

the HMI should be able (as a vision) to replace the classical cockpitinstrumentation (e.g. tachometer…)

all relevant information should be presented as easy as possible

pratical implications (financial, legal, technical limitations…) are ofsecondary importance in the first concept stage


Design of the HMI – main principles

behaviourally relevant information instead of status information no information about the actual driving speed but information about the

appropriateness of the driving speed no information about the absolute distance to another car but information

about how dangerous the situation is („risk potential“)

based on the behavioural repertoire of the driver longitudinal control: accelerating, braking lateral control: steering

Which stimuli control behaviour?


Spatial orientation

spatially oriented reactions in driving (to the left, to the right, forward, backward)

it seems reasonable to present stimuli spatially oriented asspatially oriented stimuli gain easily control over spatially orientedreactions


Stimuli

use of the dashboard behind the steering wheel

visual stimuli


Dynamic task – dynamic visualization

dynamic task

the behaviour of the driver changes the illustration in the display in a compatible way

accelerating

decelerate

appropriate

too fast

too slow


Appropriateness of driving speed

driving speed is appropriate regarding the traffic situationcar symbol is in the middle of the display

driving speed is inappropriate (too high) regarding the traffic situationcar symbol is shifted to the top of the display


Appropriateness of the distance to an object ahead

if the distance to an object aheadis too small a risk potential arises

this is illustrated by a longitudinal colour gradient


Appropriateness of the distance to the front car

distance to the car ahead is too smallyellow colour gradient from the top

distance to the car ahead is criticalred colour gradient from the top


Appropriateness of the lateral position

distance to the left lane marking is too smallyellow colour gradient from the left


Appropriateness of the lateral position

distance to the left lane marking is too small/criticalyellow/red colour gradient from

the left

distance to the right lane marking is too small/criticalyellow/red colour gradient from

the right


Further principles and elements

safety signal: car symbol is located in the middle of the display, no colour gradients are visiblepresentation of signals only if the driver has to change his behaviour (shifting the car symbol, colour gradients)

additional important information in specific critical situations if particular functions of the vehicle achieve a critical status,

e. g. the level of oil is far too low, VIDE gives short commands like “Please pull over to the side of the road and stop the engine.”


Assessment of VIDE (Goralzik, 2009)

Hypotheses

Driving with VIDE results in smaller integrals of speeding for each characteristic of the track than driving with the classical instrumentation.

This should hold for different courses of the track and zones of different speed limits.


Assessment of VIDE – Method

Configuration stage realised in the study

appropriateness of driving speed regarding the given speed limit course of the track

appropriateness of the distance to the lane markings



HMI-lab of the German Aerospace Center in Braunschweig

26 participants (mdn=38 years, range=24-59 years)

at least five years of driving practice (mdn=22 years, range=7-42 years)



km/h-max.

course of the track

rural road motor-way

straight left-handbend

right-handbend

60 + + +

80 + + + +

100 + +

120 +

130 +



comparison of driving with VIDE and driving with classical instrumentation (tachometer, revolution counter)

no vehicles ahead

classicalinstrumentation

VIDE



questionnaire to investigate several aspects of acceptance

subjective perception of safety comprehensibility comfort usefulness perceived control perceived degree of efficiency irritability conformity with expectancies appropriateness of driving behaviour intentions to use the system requests for modifications concerning the design of VIDE


Assessment of VIDE – Analysis

calculation of the integral of the actual driving speed [m/s] as a function of simulator runtime [s] when the given speed limit had been exceeded larger integrals imply a larger extent of speeding

analysis of the difference between the averaged integral while driving with VIDE and while driving with classical instrumentation with a permutation test for dependent samples (statistic: difference of means)


Assessment of VIDE – Significant results

straight parts 80 km/h: t(25)=-5,36; p<0,01 100 km/h: t(25)=-2,74; p<0,01

left-hand bends 80 km/h: t(25)=-3,64; p<0,01

right-hand bends 80 km/h: t(25)=-3,98; p<0,01

driving with VIDE caused less speeding in some of the configurations of the track when compared to the classical instrumentation


Assessment of VIDE – Questionnaire

Preferences of VIDE in comparison to the classical instrumentationItem %

„Classical display“

„New display“a

The information of which display made you feel safer? 30.8 69.2

Which display do you deem more reasonable? 38.5 61.5

Which display influenced you more while driving? 23.1 76.9

Which display made you drive more appropriately?b 11.5 84.6

„No“ „Yes“Do you believe that the new displaya allows forsafer driving? 7.7 92.3

Note. aThe notation ”New display“ corresponds to VIDE. bMissing values cause the categories not to sum upto 100 per cent.


ADAPTATION OF VIDE TO A NEW SITUATION

Research project „FAMOS – Galileo for Future Automotive Systems“(funded by the Federal Ministry of Economics and Technology)


Merging into motorway traffic

the driver is assisted in changing from the acceleration

lane onto the motorway adapting driving speed keeping an appropriate distance lane keeping

no automatic lane change!

development of different levels of assistance (German Aerospace Center) basic functions - finding a gap - guidance to a gap - partly automated

DLR


Dashboard of Volkswagen

multi-function display between revolution counter and tachometer

need for information about the driving speed (field tests)

original image: www.volkswagen.de


Adaptation to a lane change

the main elements of VIDE are kept appropriateness of the distance to a vehicle ahead and to the lane

markings illustrated by colour gradients appropriateness of driving speed illustrated by the dynamic shift of the

car symbol

the new element vehicles at the motorway produce a risk potential during and after a

lane change it is projected how large the distance to the other vehicles will be during

and after a lane change, in dependence of the driving speeds anticipated risk potential if a lane change is performed right now

illustrated by an additional lateral colour gradient


Design

transfer of the principles into a perspective design

all elements remain perspectivic adaptation realistic car symbol

fitting the information of the levelof assistance and the mode intothe display


Acoustic signals

additional assistance by acoustic signals in specific situations e.g. lane change is possible, level of assistance is changed, strategy is

changed

guiding attention enhancing attention

example: „gong“ sound which signals the possibility of a lange changewithout a risk potential


Summary

integrated HMI concept for different assistance functions

integration of behaviourally relevant data from different sources

concept of a universal interface between car and driver

possibility of coupling the behaviour of the driver and the car via an adequate HMI

possibility of integrating additional information in specific situations


Outlook

integrating more information in order to calculate the appropriateness of driving manner more accurately

adapting VIDE to the individual driver in order to effectively influence his behaviour towards a safer driving manner

identification of further situations for which the display has to be expanded or modified


Thank you very much for your attention!

Dr. Anke [email protected]

Technische Universität BraunschweigDepartment of Research Methods and Biopsychology (IPMB)

theoretically guided hmi development for a driver assistance system

Art & Photos

anke schwarze page

relevant information

status information

information manipulation

vehicle information

situationspecific reaction

simple reaction

complex reaction