- Stability program most important element in traffic safety
- Share of driver-related accidents involving Mercedes passenger cars down 42
percent
- Improved occupant protection in passenger cars thanks to Mercedes
innovations
- Passenger car development in a conflict of goals between Euro NCAP and
practical experience with accidents
- PRE-SAFE to be equipped in the future with a radar sensor to help prevent
accidents
- New Mercedes book on safe driving
The Electronic Stability Program (ESP) developed by Mercedes-Benz, which
reduces the risk of skidding and helps drivers to better deal with critical
driving situations, has led to greater safety on German roads and motorways.
After five years of having the system included as standard equipment in Mercedes
vehicles, the Stuttgart-based brand has registered a significant decrease in
so-called driver-related accidents in which drivers lose control of their
vehicles, skid and drive off the road. "If all automobiles were equipped with
the stability system, more than 20,000 such serious accidents, which claim over
27,000 victims each year, could be prevented in Germany," says Dr. Thomas Weber,
DaimlerChrysler Board of Management member for Research and Technology and head
of Development at the Mercedes Car Group.
Since being fitted with ESP as standard equipment, Mercedes passenger cars
have been involved in serious driver-related accidents far less frequently than
vehicles from other brands. The average share of newly registered Mercedes
models involved in such accidents in 1998/1999 was 20.7 percent. ESP helped to
reduce this figure by more than 42 percent in 2002/2003. At the same time, the
share of passenger car models from other brands involved in these types of
traffic accident fell by only about 13 percent.
Driver-related accidents are one of the most severe types of accident that
can occur: In 2003, 43 percent of all traffic fatalities and 20 percent of all
injuries were due to driver-related accidents.
"Along with seatbelts, airbags and ABS, ESP is by far the most important
safety system in today’s passenger cars," says Weber. "The invention of ESP and
the inclusion of this technology as standard equipment have enabled
Mercedes-Benz to set an important trend in improving traffic safety."
The system does in fact offer tremendous potential for preventing serious
accidents. Moreover, ESP also helps to reduce the extent of injuries to vehicle
occupants in an accident. For example, because the system stabilizes vehicles in
a skid, the risk of dangerous side collisions with trees, poles or other objects
at roadsides is reduced. Following the installation of the stability program as
standard equipment in Mercedes-Benz passenger cars, the proportion of collisions
resulting in the most severe injuries fell from 15 to five percent.
The results of Mercedes-Benz accident studies also show that passenger cars
equipped with ESP roll over less frequently than vehicles not equipped with this
safety system. Thanks to ESP®, the proportion of Mercedes-Benz vehicles involved
in rollover accidents has decreased by around 12 percentage points.
Studies conducted in the USA and Sweden also confirm the
positive impact the system has had in reducing accidents or mitigating their
consequences. The American Insurance Institute for Highway Safety has
determined, for example, that ESP can reduce the number of fatal traffic
accidents by more than one-third (34 percent).
ESP celebrated its world premiere at Mercedes-Benz in 1995 and has been
included as standard equipment in all the brand’s passenger car models since the
summer of 1999. Half of all newly registered vehicles in Germany are currently
fitted with the system, with the proportion of small cars so equipped at
under ten percent. Approximately one-third of all new passenger cars in the
European Union are fitted with the safety system.
Statistics show that Mercedes innovations help reduce the number of
accidents
The Electronic Stability Program is the result of safety developments at
Mercedes-Benz that are based on analyses of real situations and the knowledge
gained from accident research. Other technological milestones that
benefit the occupants of all passenger cars, such as the crumple zone, airbags,
seat belt tensioners, offset layouts, and side and window bags, are also based
on this development principle.
As such, Mercedes-Benz has been a trendsetter in passenger car safety
for exactly 65 years. The brand has also made a major contribution to the
continual reduction of the number of injured vehicle occupants that has
been registered in Germany, with a decrease of more than 41 percent recorded in
the period between 1993 and 2003 alone. The number of drivers and vehicle
passengers killed in traffic accidents fell by more than 38 percent to a record
low during the same period.
Having developed a series of pioneering inventions that have been proven to
enhance occupant safety, Mercedes-Benz has spent the last few years focusing on
accident prevention. Technological milestones such as ESP, the ABS anti-lock
braking system (ABS), the ASR acceleration skid control system, Brake Assist
(BAS) and Active Body Control (ABC) have made Mercedes a pioneer and trendsetter
in the field of accident prevention as well. The ultimate goal of Mercedes
engineers is the “vision of accident-free driving."
As was the case with airbags, seatbelt tensioners, ABS and ESP®, the
development of future Mercedes safety systems will also be primarily based on
analyses of actual accidents and extensive practical tests.
Safety system development: Contradictory goals as a result of laboratory
tests and data from actual accidents
Safety-system development at Mercedes-Benz thus differs from other goals that
focus mainly on the demands of laboratory tests such as the Euro NCAP
procedures, rather than the knowledge gained from research into actual
accidents. "Using standard crash tests like the Euro NCAP procedures as the
sole testing and assessment criteria for judging safety in new automobiles is
not the right path to follow, as it does not allow us to take into account the
way accidents actually occur," says Weber.
Mercedes considers the "European New Car Assessment Program," which awards
the well-known safety stars as a certificate, to be quite helpful in terms of
informing car buyers about occupant protection in new models. However, the
crash tests stipulated by NCAP cover only approximately one-third of the
actual circumstances surrounding accidents. Moreover, this proportion
falls significantly when one additionally takes into consideration the exact
severity of various accidents. For this reason, Mercedes believes that NCAP
harbours a risk in that vehicles could be designed primarily in a manner that
ensures they fulfil the test requirements, and might therefore not offer
sufficient occupant protection in many types of accidents.
Mercedes experts point to head-on collisions as an example, whereby it is
often the case that vehicles of differing sizes and weights crash into one
another. In such situations, an extremely rigid front structure does not always
offer the best occupant protection, despite the fact that it leads to the best
results in the Euro NCAP head-on collision test.
"Many safety innovations over the last few years have not had any influence
on the results of the Euro NCAP tests, and their protective functions have not
been awarded with safety stars," says Weber. “In practice, however, these
systems are important in ensuring the best possible protection for vehicle
occupants in all types of accidents."
PRE-SAFE: Preventative safety system to include short-distance radar in
future
The PRE-SAFE preventative occupant protection system, which was also
developed on the basis of knowledge gained through accident research, makes it
possible for the first time to prepare the vehicle and its occupants for an
impending accident just seconds before it occurs. In such a situation, the
system automatically tightens the front seatbelts and places the front passenger
and separate rear seats into an optimum position. It also closes the sunroof if
it senses that the vehicle is about to roll over. "PRE-SAFE heralds a new era of
vehicle safety," says Weber.
In future, Mercedes-Benz will further develop PRE-SAFE into an even more
versatile system and create a direct link between active and passive safety — in
other words, between accident prevention and occupant protection. For example,
Mercedes engineers are now working on a radar-assisted sensor system that
will monitor the immediate area in front of and on the side of the vehicle up to
a distance of approximately 30 metres. This future PRE-SAFE technology will be
able to autonomously sense danger and then act in a pre-emptive manner. If, for
example, it appears that the vehicle is about to collide into the car in
front of it, the system will not only tighten the seatbelts but also prepare
the brakes for engagement. This means that as soon as the driver hits the brake
pedal, the brake pressure needed for the situation at hand will be made
available. This can significantly reduce braking distance.
In further development stages, the short-distance radar will serve as the
basis for an autonomous PRE-SAFE braking system that will automatically
engage in situations when the only way to prevent an accident or mitigate its
consequences for occupants is by making an emergency stop.
Brake lights: Blinking lights as an effective warning signal to prevent
rear collision
For some time now, Mercedes safety engineers have been focusing on the high
number of rear-end collisions that occur, which is why they have developed a
technology alongside PRE-SAFE’s sensor system that can be quickly implemented in
all vehicles and thus help to counteract the trend: Blinking brake lights, which
in the form of a red, blinking warning signal instead of conventional stop
lights can reduce a driver’s braking reaction time by up to 0.2 seconds,
according to tests conducted by Mercedes engineers. This translates, for
example, into an approximately 4.4-metre reduction of the braking
distance for a car travelling at 80 kilometres per hour — something which
would lead to much greater safety in dense traffic. The study conducted by the
Mercedes engineers also revealed that switching on the warning signal in
dangerous situations has only a minor effect on a driver’s reaction time.
Brake Assist: Technology that helps prevent accidents involving
pedestrians
Brake Assist, which Mercedes-Benz was the first carmaker to introduce in
1996, has also proven to be an effective instrument for accident prevention. The
system supports drivers who engage the brakes quickly enough but not hard enough
in dangerous situations by ensuring maximum braking deceleration at lightning
speed.
A recent study conducted by Mercedes engineers shows that Brake Assist also
makes an effective contribution towards preventing accidents involving
pedestrians. This study had 55 drivers take part in a test at a driving
simulator in Berlin. While driving through a town at a speed of 50 kilometres
per hour, the test subjects would suddenly see a child run in front of the car
from the left side. An emergency stop was the only way to avoid an
accident here. The results of the test showed that drivers whose cars were
equipped with Brake Assist caused significantly fewer accidents than drivers
without the system, with the accident rate dropping by 26 percentage
points.
New book on safe driving
In cooperation with the Hampp publishing house in Stuttgart, Mercedes-Benz
has published the book "Sicher Auto fahren" (Driving Safely) as a
reference guide on all issues related to traffic safety. The 160-page book
provides details on the development of pioneering Mercedes safety systems and
their technology. It also contains around 150 tips for defensive and
alert driving and offers an interesting look at the passenger car safety
technology of tomorrow.
"Sicher Auto fahren" (ISBN 3-930723-45-X) will go on sale in bookstores and
dealerships, and at Mercedes-Benz sales partners, at the end of November 2004.
It will also be available directly from Hampp-Verlag (www.hamppmedia.de). The price is 39 euros.
Electronic Stability Program (ESP)
In the summer of 1999, Mercedes-Benz became the first automaker to fit all of
its passenger car models with the Electronic Stability Program as standard,
thereby making an important contribution to the improvement of road safety.
ESP works according to the principle of a "permanent monitor", whereby
sensors observe the driver’s and the vehicle’s behaviour and then send their
data to a high-performance control unit loaded with a mathematical model. As a
result, the actual condition of the vehicle is continuously compared to a
reference value provided by the driver. The system is thus able to sense when
the vehicle is in danger of skidding.
When the ESP computer registers a discrepancy between the two values, it
engages at lightning speed according to a specially developed logic system on
the basis of which it applies precise dosages of braking power to the front or
rear wheels, and also adjusts the engine torque. If, for example, the vehicle’s
rear axle swings too far outwards when taking a curve, ESP will lower the drive
torque, thereby increasing the lateral guidance force of the rear wheels. If
this action fails to produce the desired result, the system will apply precise
brake pressure to the front wheel on the outside of the curve in order to
stabilise the vehicle. The braking impulses counteract the critical rotary
movement, while the simultaneous deceleration provides an additional safety
effect.
Unlike the acceleration skid control system, which assists the driver when he
or she accelerates the vehicle, ESP is available to go into action at any time —
during braking, acceleration, or cruising along. ESP immediately adapts to the
vehicle’s movements and continues to engage until there is no longer any danger
of skidding.
Brake Assist
During tests conducted with a driving simulator, Mercedes engineers
discovered that although drivers may implement emergency stops quickly, they
often do not step on the brake pedal hard enough. This discovery led to the
development of Brake Assist, which Mercedes-Benz was the first to include as
standard equipment in its vehicles, and which is now standard in all Mercedes
passenger car models.
Brake Assist interprets the brake pedal being engaged at a specific speed as
indicative of an emergency situation. It then automatically generates maximum
brake boosting power within a fraction of a second, thereby reducing braking
distance significantly.
Brake Assist is integrated into the ESP system in today’s Mercedes passenger
cars. It uses ESP technology to regulate braking pressure, making additional
components unnecessary. A sensor continually registers the speed at which the
brake pedal is engaged and sends this data to the electronic control unit.
If the speed at which the pedal is engaged should suddenly exceed the norm,
the system will conclude that there is an emergency braking situation. It will
then assist the driver in the emergency stop and automatically raise the braking
pressure in the wheel brake cylinders.
There is no danger of the wheels locking during this automatic hard stop, as
ABS continues to apply precise braking power dosages up to the slip limit and
the vehicle thus remains steerable. If the driver removes his or her foot from
the brake pedal, the automatic power reinforcement deactivates immediately.
PRE-SAFE
The PRE-SAFE pre-emptive occupant protection system that premiered in the
S-Class in 2002 marked the beginning of a new era in vehicle safety at
Mercedes-Benz. PRE-SAFE is a preventative system that recognises critical
driving situations that could lead to an accident, and goes into action
immediately to prepare both occupants and the vehicle for a possible collision
by:
- Tightening the driver and front passenger seatbelts as a preventative
measure.
- Putting the front passenger seat into a better position if it should be
disadvantageously situated, and improving the angle of the backrest and seat
cushion.
- Activating the electrically adjustable individual rear seats to improve the
angle of the seat cushions.
- Automatically closing the sunroof if the vehicle is in danger of rolling
over.
Thanks to the preventative protective measures undertaken by PRE-SAFE,
vehicle occupants are placed into a better sitting position that ensures that
seatbelts and airbags will work more effectively. If the accident is avoided,
the preventative tensioning of the seatbelts is automatically deactivated,
allowing the occupants to return the seats and the sunroof to their original
positions.
PRE-SAFE is able to prepare for an accident by combining elements of active
and passive safety to create a synergy that is unique in the world to date:
PRE-SAFE is networked to the ABS anti-lock braking system, Brake Assist and the
Electronic Stability Program (ESP), all of whose sensors can recognize dangerous
driving manoeuvres and send the corresponding data within seconds to the control
units for these standard safety systems. Mercedes-Benz uses this sensor data for
its preventative occupant protection system. In future, PRE-SAFE will be
outfitted with additional features for preventing accidents, including a system
for autonomous or semi-autonomous braking in critical situations.
|
