In 2002, with PRE-SAFE®, Mercedes-Benz vehicles started learning to respond before an accident occurs. These functions have improved more and more over time. More new aspects are added with the ESF 2019: PRE-SAFE® Curve and PRE-SAFE® Side lighting defuse situations where the accident risk suddenly increases but can be avoided. At the end of tailbacks, PRE-SAFE® Impulse Rear improves the protection of passengers and others involved in an accident.
Even in vehicles that can already automatically take over driving functions, the driver will be able to drive the vehicle if desired – and do so for personal enjoyment. Intelligent onboard systems can provide support in this case. PRE-SAFE® Curve uses the reversible belt tensioners if the driver approaches a bend at high speed. The belts are tensioned well before the bend is reached, so that the driver receives a warning and can still reduce the speed. At the same time the passengers receive improved support from the increased belt tension when negotiating the bend.
The car also warns other road users (in cross-traffic) with the PRE-SAFE® Side lighting function. This based on electro-luminescent paint (for details see profile).
PRE-SAFE® Impulse Rear attempts to prevent an impending rear-end collision, or to mitigate its effects, by briefly accelerating the car forwards at the last moment. The ESF 2019 maintains the same distance at the end of a tailback as a careful driver. When the system recognises that the vehicle behind is about to cause a rear-end collision, it briefly accelerates the car into the gap between it and the vehicle ahead, then brakes it to a stop. This increases the chance of avoiding an accident, as traffic behind has a longer braking distance available. Moreover, the consequences are less serious for the occupants of the ESF 2019 if the impact is unavoidable, as they have already been accelerated forward and the relative speed is lower. The resulting movement of the occupants is another advantage. This is because the occupant is forced back into the seat before a possible rear impact, so the head is resting against the head restraint. This can further reduce the risk of typical neck injuries (whiplash). Crash simulations have shown that acceleration impulses lasting just a few hundred milliseconds can considerably reduce the impact energy.
An electric drive system is able to generate very high acceleration impulses, and its torque is available from standstill. Accordingly an electric vehicle needs less than one metre to accelerate to over 7 km/h.