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Official statistics cite fatigue as the reason behind
approximately one percent of all serious traffic accidents. However, experts
believe that the number of accidents where fatigue is a factor is significantly
higher, as fatigue is often a factor which is impossible to ascertain or prove
when reconstructing the accident. According to the latest European studies, 24
to 33 per cent of all fatal traffic accidents involve overtired drivers. This
means that fatigue may be responsible for a higher proportion of serious traffic
accidents than alcohol.
In addition to the lack of a good night's sleep, one of the
most frequent causes of the dangerous phenomenon of nodding off at the wheel is
monotony. Two thirds of accidents caused by fatigue occur in the dark, and half
where there is little traffic around. Scientists believe that the risk of
accident is particularly increased on long-distance journeys under unchanging
conditions, as this causes the driver's attention to tail off and monotony also
increases the risk of falling asleep.
Investigations by Mercedes engineers involving over 420 car
drivers to date, show that many people fail to recognise the signs of fatigue or
do not spot them at an early enough stage. Fatigue does not generally make
itself felt in sudden bursts - it gradually builds over time. The driver's
reactions and perceptual capacity gradually diminish to such an extent that,
even in the early phases of fatigue, drivers are often unable to react
appropriately.
The assistance system developed by Mercedes-Benz is designed
to detect the early signs of fatigue and warn the driver. Therefore making an
important contribution to the prevention of accidents.
Individual driver profile based on various
indicators
Unlike other methods of detecting fatigue, the Mercedes system
evaluates a
series of indicators in order to assess the alertness of the
driver and to recognise the gradual transition between being awake and being
tired. During every journey Attention Assist continuously observes the driver's
typical behaviour patterns and uses these to create an individual driver profile
which serves as a basis for recognising the symptoms of fatigue. Where there is
a significant deviation from the saved empirical values, the system determines
whether or not there are signs of impending fatigue. Whether and when the driver
is warned also depends on the time of day, the duration of the trip and the
individual's driving style.
Steering behaviour as the key indicator of
fatigue
The values recorded by the fatigue recognition system not only
include the speed and longitudinal and lateral acceleration, but also the angle
of the steering wheel, the way that the indicators and pedals are used, certain
driver control actions and various external influences such as a side wind or an
uneven road surface. Observation of the steering behaviour has proven
particularly significant: tired drivers can be spotted by a series of typical
steering wheel movements which they then immediately correct. The new Mercedes
assistance system recognises signs such as these. If the driver's steering
behaviour changes and other indicators also point towards encroaching fatigue,
the system outputs a warning at an early stage. A warning signal sounds and a
symbol in the instrument cluster advises the driver to take a break.
Over 500,000 kilometres covered to date in worldwide
tests
The development of this unique assistance system began with a
series of experiments in a driving simulator in Berlin. These were followed by
daytime and night-time motorway trials. Over 420 people have taken part in these
trials to date and have covered a total of over 500,000 kilometres to date. The
test programme for Attention Assist will be rounded off with long-term trials in
various climate zones, in city traffic, on poor roads and on long-distance
trips. The Mercedes development team for this system not only includes engineers
but also cyberneticists, mathematicians, computer scientists and psychologists.
Complementing the familiar driver assistance
systems
When developing driver assistance systems, Mercedes-Benz has
always focused on real accident data and develops technologies which are
designed to improve driving safety in critical situations. The focus to date has
been on those accidents with particularly serious consequences: front-end
collisions, rear-end collisions, night-time collisions and accidents involving
pedestrians. Attention Assist continues Mercedes-Benz's practice-oriented
commitment to preventing accidents and complements familiar driver assistance
systems such as ABS, Brake Assist, Brake Assist PLUS, PRE-SAFE brake, the
infrared nightview system and ESP, which monitor the vehicle and its
surroundings. The fatigue recognition system is the first technology to observe
the driver on a continual basis too and to use typical behaviour patterns to
detect the risk of an accident and provide a warning. Series production of the
system is planned for 2009.
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