Electronic Brake Systems from Continental Teves - for Greater Safety, Comfort and Driving Pleasure

DETROIT, March 9 -- The first Electronic Brake System -- the ABS MK 20 -- was launched by Continental Teves in 1984. Since then, EBS systems have lost roughly 80 percent in weight and costs have come down as much as 90 percent. Modern systems also boast dramatically improved performance -- as demonstrated by the state-of-the-art Electronic Stability Program (ESP). And that trend is set to continue.

Active Rollover Protection (ARP): Less risk of rolling

Rollover accidents often have very serious consequences. As rollover is normally the result of skidding and losing control of the vehicle, ESP provides a good primary source of protection. But SUVs, minivans and pickups with their specific design characteristics -- high center of gravity, narrow track and long suspension travel -- can reach a critical rollover situation before ESP is able to measure hazardous lateral acceleration values. So for vehicles like these, Continental Teves developed ARP (Active Rollover Protection) -- a system which automakers are now installing more and more frequently.

Using signals from the ESP sensors, ARP continuously analyzes the vehicle's dynamic situation and steering-wheel movements, plots potential emergency scenarios and implements them lightning fast when danger threatens. If ARP detects a rapid steering movement typical of evasive action, it brakes the front wheel on the outside of the bend, reducing the forces acting on the side of the vehicle, cutting lateral acceleration, and reducing speed. This way, ARP counteracts critical body roll before it starts to cause the kind of dynamic changes in wheel load that lead to rollover.

New EBS generations: Analog valves and added functionalities

In the new MK 60 EBS generation, Continental Teves has replaced digital hydraulic valves -- which can be either fully open or fully closed -- with valves with analog control, which are infinitely variable. This makes for shorter stopping distances, minimized pedal vibrations and finely tuned pressure build-up for the automatic Adaptive Cruise Control (ACC) braking function. The MK 60 can also use the ABS pump for brake boosting, not least to prevent a dramatic increase in the required pedal force caused by brake fading and to support the driver in the event of a brake booster failure.

In combination with the analog valves, the ABS hydraulic system's brake booster function also helps when the engine does not generate enough vacuum to ensure reliable brake boosting. This is the case immediately after a cold start, as well as with direct-injection engines optimized for high efficiency. Further potential for improving stopping distances and stability is created by adding brake pressure sensors on all wheels. With these sensors, ABS need no longer be controlled indirectly -- based on wheel speed and slip -- but can be governed directly as a function of the brake pressure measured. Continental Teves is set to launch its new EBS generation this year.

ESP II: Networked steering and brakes

Today, brake systems are already being networked with intelligent air- sprung chassis with adaptive dampers. In the next step down the road to Global Chassis Control (GCC) which will involve a central control unit for all safety and comfort/convenience-related chassis functions, Continental Teves is extending ESP II to include external steering control. The outcome, when parking or cornering at speed, will be a very direct steering ratio, reducing the required movement of the steering wheel to a minimum.

The vehicle thus becomes much more responsive when cornering, particularly when ESP II enhances performance by turning the wheels further into the bend for an instant than actually called for by the steering wheel movement.

For fast, straight driving, the steering is less direct, reducing the risk of swerving as a result of rapid movement of the steering wheel. With its ability to influence the brakes, steering and engine simultaneously, ESP II also makes a highly effective dynamic handling control system, capable of substantially enhancing directional stability through targeted intervention at the front wheels. As a result, automatic brake operation by ESP can cut in later and more gently.

Optionally, if the vehicle is equipped with air springs and/or adaptive dampers, the system can also control the chassis. The key advantages here are that, with its dynamic limits no longer so narrowly defined, the vehicle is easier to control at the limit, while load changes are offset for much more effectively and comfortably. When braking on roads with different grip on either side of the vehicle (u-split braking), ESP II also makes for much shorter stopping distances with minimum steering intervention and optimized directional stability.

With 2002 sales of approximately $12 billion (US), Continental AG is a major supplier of brake systems, chassis components, vehicle electronics, tires and technical rubber products. Continental Automotive Systems' North American operation is headquartered in Auburn Hills, Mich. For additional information, visit these websites: www.conti-online.com and www.contitevesna.com .