- Third generation of the anti-lock braking system (ABS3) now responds with even greater speed and precision thanks to enhanced brake pressure control
- Optimum brake performance is ensured with a more adaptive controller design
- Test drives conducted on different road surfaces confirm the unleashed performance potential of ABS3
Auburn Hills, Mich., March 19, 2018 - Safe, controllable and optimum brake performance at all times are just some of the things drivers want from their brake systems and result in increased automation. Technology company Continental responds to this trend by developing a third-generation ABS (ABS3) and securing additional safety potential for achieving the long-term vision of accident-free driving – Vision Zero.
This new generation adapts the brake pressure control with even greater speed and precision for changing road conditions. This means the vehicle remains more maneuverable, even when the brakes are applied sharply, ensuring optimum brake performance under difficult circumstances. For example, when the brakes are applied on road surfaces with different friction coefficients (μ-split situations) such as the lane on the right is covered in leaves, snow or gravel, while the lane in the middle has a stronger gripping surface. When this occurs, the ABS has to apply completely different levels of force to the wheels on the left and right to ensure maximum deceleration without compromising vehicle stability.
“To ensure optimum brake performance and maneuverability at all times, even under ever-changing conditions, ABS3 takes these changes into account more quickly and robustly when controlling the wheel dynamics,” said Robert Beaver, Chief Engineer Electronic Braking Systems business unit at Continental. “Thanks to the ability of ABS3 to quickly respond to changes, drivers can retain control over their vehicles more effectively at the crucial moment and feel much safer as a result,” said Beaver.
The ABS3 responds even faster than the previous generation to abrupt changes in the level of road grip. A typical example is when a driver executes a full braking maneuver starting on a slippery road surface and ending on a strong gripping one – a scenario known as a “low-µ/high-µ jump.” This causes the lock-up pressure level to change. Even when this occurs abruptly, ABS3 can handle this more effectively than ABS2 due to its dynamic response and adaptive controller structure.
During winter test drives conducted in four different vehicles – each equipped with ABS2 or ABS3 and fitted with predecessor or current tire models – at the Continental test site in Arvidsjaur, Sweden, the benefits of ABS3 for both tire generations were clear to see. The planned test maneuvers included not only different surface situations (the μ-split and low-μ/high-μ jump), but also a lane change with the brakes applied.
ABS3 offers numerous benefits
ABS and electronic stability control (ESC) have made a key contribution to improving road safety and saving lives, which is why these systems are offered as standard by most manufacturers. Today, they are generally considered the most important step on the road toward safer driving. ESC in today's version is an extension of the ABS. The ABS prevents the wheels from locking when the driver is braking so that the vehicle remains capable of being steered. The ESC prevents the breakaway of the vehicle through targeted braking interventions by the electronics. Both systems complement each other offering maximum safety and optimum driving stability within the physical limits. The generic concept behind ABS3 means that specific situations (e.g. μ-split) do not need to be detected and applied. These benefits mean the third-generation ABS is much easier than ABS2 to apply in different vehicle models.
In another scenario, if a driver decides to have tires with optimized rolling resistance fitted to their car for environmental reasons, the ABS is designed to respond perfectly to this change. Using a model-based concept, the adaptive controller in ABS3 more effectively allows for different tire performance. With ABS3, drivers who decide to have tires with optimized rolling resistance fitted to their car benefit from the fact that this allowance for changed tire behavior helps to improve the braking effect. Most drivers may not necessarily be aware of this interaction but with ABS3 they can be confident they have the right safety system for their new tires.
The tire transmits power between the vehicle and the road in all driving situations. The ABS anti-lock braking system is representative for vehicle control systems. The ABS ensures optimum slip even during emergency braking, which means the maximum possible braking force is transferred from the tire to the road surface (µ-slip curve). Despite this, the vehicle remains maneuverable because the wheels are prevented from locking up. This control procedure is extremely demanding because it has to occur very dynamically. In addition to the manageability and steerability of the vehicle during emergency situations, the ABS must ensure that the friction potential of the tire is optimally exhausted, especially in the longitudinal dynamics. And, as drivers are all too aware from the annual tire tests, the quality of the tire itself also plays a key role. ABS3 pays particular attention to the fact that the interaction between the tires and road surface is influenced by a whole range of factors, some of which – road friction, temperature, vehicle load and speed – change all the time.