Press Release
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New sensor fusion approach recognizes rain, snow
and ice on the road
Continental is working on an early warning system for road sections with low grip
Regensburg/Germany, October 12, 2010. The international automotive supplier Continental
is using its know-how in the development of a variety of sensors, for future applications that
inform drivers about potentially slippery road sections as early as possible. Because even the
best active safety systems cannot cheat the laws of physics, Continental, together with
partners, has developed a new approach to sensor fusion. This new system will give the
driver an advance warning about low grip. It was developed within the “Friction” project as
part of the 6th Framework Programme, co-funded by the European Commission.
Without enough friction between tires and road (good “grip”), there is no way of keeping a
vehicle under control. Active safety systems such as ABS (antilock braking system) and ESC
(electronic stability control) will help in situations when emergency braking or imminent
skidding put a driver’s skill to the ultimate test. However, even such valuable systems as
ABS and ESC will only react, when the vehicle is already in danger of getting out of control.
Realistically it is entirely up to the driver to estimate whether there is enough grip to allow for
the vehicle’s current speed.
Fusion of many vehicle and environmental sensor data
The new sensor fusion approach uses data from vehicle dynamics sensors and interprets
them together with information that comes from additional environmental and tire sensors.
The basic idea is to inform the driver as soon as he or she gets too close to the limits of
friction between tire and road.
For that purpose the system estimates the required friction (friction used) for a particular
driving manoeuvre, estimates the maximum available friction (friction potential) and
calculates the difference. While this sounds easy, integrating the many vehicle and
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Your contact person:
Enno Pflug, +49 6196 87 2515
-2environmental sensor signals and achieving a reliable decision-making mechanism is in fact
quite complex.
Vehicle dynamics sensors
In-vehicle sensors provide the data to estimate the friction between tires and road. The
research vehicle uses two strategies to estimate friction by calculating the vehicle’s dynamic
response. The Continental approach computes amongst other things longitudinal and lateral
acceleration, wheel speeds, yaw rate and steering wheel angle. Based on a lateral dynamics
model that describes how the vehicle should react under ideal conditions, the actual vehicle
reaction indicates the current level of friction.
During the sensor fusion development this approach was combined with a second way of
friction estimation which is based on steering torque. This alternative strategy was developed
by the Centro Ricerche Fiat.
Environmental and tire sensors
Environmental sensors provide data to the second sub-module which computes the
environmental features:

An optical sensor measures changes in the amount of light that is reflected by the
road surface directly in front of the front wheel (0.4 to 1.5 meters ahead).

A polarization camera detects differences in vertical and horizontal polarization
caused by road surface conditions between 5 and 20 meters in front of the vehicle.

Finally, a laser scanner checks the weather conditions by detecting objects such as
snow flakes or rain drops within a range of 50 to 100 meters ahead of the vehicle.

The road surface temperature is measured by a thermometer.

An air thermometer measures the ambient temperature.
In addition the intelligent tire sensors, which are integrated into the tires, deliver information
about the current tire distortion of the rolling tire. The system warns against early stages of
aquaplaning.
By computing the data from the environmental sensors and checking their plausibility against
the thermometer readings, the system can detect the road conditions and thus potential
threats to friction.
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-3To warn drivers the complete sensor output and sub-module results are integrated into a tireroad friction value. This information can warn the driver in time and it can make collision
mitigation or collision avoidance systems more efficient under adverse weather conditions.
Displaying the information to the driver
In addition to developing the new sensor fusion approach, Continental, as a specialist in
driver information, is in the ideal position to inform drivers quickly about the road condition –
and to do so in a way that is adequate for task of driving. For designing an ergonomic visual,
acoustic and potentially also haptic warning message to the driver, Continental can use its
portfolio of cockpit instrumentation. In addition to the cluster instrument, the head-up display
for instance can offer ergonomic advantages to communicate the safety critical friction
warning.
With sales of approximately €20 billion in 2009, Continental is among the leading automotive
suppliers worldwide. As a supplier of brake systems, systems and components for powertrains and
chassis, instrumentation, infotainment solutions, vehicle electronics, tires and technical elastomers,
Continental contributes to enhanced driving safety and global climate protection. Continental is also a
competent partner in networked automobile communication. Continental currently employs
approximately 143,000 in 46 countries.
The Automotive Group with its three divisions Chassis & Safety (sales of approximately €4.4 billion
in 2009, 27,000 employees), Powertrain (sales of approximately €3.4 billion in 2009, 24,000
employees) and Interior (sales of approximately €4.4 billion in 2009, 27,000 employees) achieved
sales of approximately €12 billion in 2009. The Automotive Group is present in more than 130
locations worldwide. As a partner to the automotive and commercial vehicle industry, it develops and
produces innovative products and systems for a modern automotive future in which cars provide
individual mobility and driving pleasure consistent with driving safety, environmental responsibility and
cost-efficiency.
The Chassis & Safety division develops and produces electronic and hydraulic brake and chassis
control systems, sensors, driver assistance systems, air bag electronics and sensors, washer systems
and electronic air suspension systems. Its core competence is the integration of active and passive
driving safety into ContiGuard®. The Powertrain division integrates innovative and efficient system
solutions for vehicle powertrains. The comprehensive range of products includes gasoline and diesel
injection systems, engine management, transmission control, including sensors and actuators, as well
as fuel-supply systems and components and systems for hybrid and electro-drives. Information
management is at the very heart of the Interior division, which provides a range of products that
includes instrument clusters and multifunctional displays, control units, electronic car-entry systems,
tire-monitoring systems, radios, multimedia and navigation systems, climate control systems,
telematics solutions and cockpits.
Editorial Contact:
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Your contact person:
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-4Enno Pflug
External Communications, Interior division
Continental Automotive GmbH
Sodener Strasse 9
65824 Schwalbach am Taunus
Ph.: 06196 87-2515
Fax: 06196 8779-2515
enno.pflug@continental-corporation.com
www.continental-press.com
Your contact person:
Enno Pflug, +49 6196 87 2515
www.continental-corporation.com