The new Mercedes-Benz B-Class: Under the microscope - Radar-based collision warning system
Rear-end collisions account for around 22 percent of all accidents involving casualties or fatalities in Germany today. The corresponding figure for the USA is as high as 31 percent. Detailed analysis by Mercedes-Benz's in-house accident research department indicates that almost half of these rear-end collisions could be avoided or the severity of impact could be reduced with the aid of radar-based safety systems such as COLLISION PREVENTION ASSIST and adaptive Brake Assist. This analysis drew on the experience acquired with the Mercedes-Benz innovations DISTRONIC PLUS and BAS PLUS.
The next milestone has been reached in the democratisation of automotive safety technology: the new B-Class generation from Mercedes-Benz will be the first car worldwide in the compact segment to offer radar-based collision warning with adaptive Brake Assist as standard. The company expects the introduction of this technology to have a significant positive effect on accident statistics. This expectation is backed up by test results: during tests with 110 car drivers in the driving simulator, the accident rate in three typical situations fell from 44 to eleven percent, thanks to a combination of COLLISION PREVENTION ASSIST and adaptive Brake Assist.
The new assistance system fits the bill precisely here: it is able to provide a driver who may be distracted with visual and acoustic warnings and to prepare Brake Assist for precision braking. Braking is initiated as soon as the driver steps emphatically on the brake pedal.
Radar-based COLLISION PREVENTION ASSIST with adaptive Brake Assist
- is able to recognise an inadequate distance from a vehicle ahead in the speed range between 30 and 250 km/h and to warn the driver
- recognises when the gap is decreasing. In case of a detected imminent danger of collision, the driver is provided with a visual and acoustic warning
- is able to recognise stationary objects ahead of the vehicle at a speed of up to approx. 70 km/h and output corresponding warnings
- is able to adapt the activation threshold for the warning and adaptive Brake Assist to given driving situations, e.g. bumper-to-bumper traffic
- calculates the precise braking force ideally needed to avoid an accident when a danger of a collision is detected and makes best possible use of any distance remaining. This means that the driver behind also has better chances of preventing a rear-end collision
The brake pressure is adjusted if the situation changes – if the vehicle ahead accelerates, it is decreased to the level the driver requires; if the distance to moving and stopping vehicles decreases, the brake pressure is increased further. When PRE-SAFE® is on board, COLLISION PREVENTION ASSIST provides one of the activation parameters for the preventive safety systems (e.g. belt tensioner).
The new system meets the key "Forward Collision Warning" requirements of the NHTSA, the American road and vehicle safety authority.
Source: Daimler AG
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