Reducing The Risk Of Rear-end Collisions

13th September 2011

ES Admin

0 0

In future, the Bosch predictive emergency braking system will also function at low speeds. If the system detects an impending rear-end collision, it now automatically triggers optimum emergency braking even if the vehicle is travelling at less than 30 kilometres per hour. This function often helps prevent rear-end collisions altogether. The “Centre for Technology” of German insurance company Allianz calculated the benefits of such emergency braking systems back in 2009. The study showed that, if all vehicles were equipped with such a system, more than 500,000 minor collisions could be prevented each year in Germany alone. This is equivalent to repair costs of 330 million Euros per year. This new function is an enhancement of the existing predictive emergency braking system, which was taken into series operation in 2010 and is now installed in several Audi and Volkswagen models. The new version for low speeds is to make its debut in the new Audi A5.

The emergency braking system in the A5 features two Bosch components – an LRR3 (Long-range Radar Sensor) for detecting objects and the ESP® (Electronic Stability Program). At speeds of less than 30 kilometres per hour, there is often little distance between a car and the vehicle in front, which means there is precious little time between the detection of a critical situation and the required braking operation. As a result, the driver cannot be given tiered warnings. If the vehicle falls below the set minimum distance and the differential speed is too high, the system brakes immediately. To be able to decelerate as quickly as possible, the brake pads are put in position shortly before the braking operation. This action goes unnoticed by the driver, but it reduces the pressure build-up time by a crucial few milliseconds.

At higher speeds, the system still provides support on a number of levels. It warns the driver – first with an acoustic or visual warning, then by briefly jerking the brakes. If the driver does not react, a partial braking operation is performed, thus extending the time the driver has to respond to the impending accident. If the driver then applies the brake, but his response is insufficient, the system increases deceleration. The aim is to stop the car before it collides with an obstacle, or slow down sufficiently to avoid an accident. This is known as target braking. The driver is now afforded effective support in all driving situations – at higher speeds on highways, on freeways and, in future, on congested city streets.