In a collision the rear of the active bonnet is raised in an instant, thus increasing the available deformation space and substantially reducing the risk of injury to pedestrians.
The new active bonnet system improves pedestrian protection: in an accident, a spring system raises the rear of the active bonnet by 50 mm in a matter of milliseconds. This results in greater deformation space, and the reversible system can be reset manually. Smooth-surfaced bodywork, energy-absorbing bumpers, flush-fitting door handles, laminated windscreens, folding exterior mirrors and recessed windscreen wipers have been defining features of Mercedes-Benz models for many years now in the interests of pedestrian protection. In addition, the front bumper on all Mercedes-Benz models features a flush-fitting spoiler lip with foam filling, which provides early and evenly distributed support for pedestrians in the event of a collision. An additional protective measure is the newly developed active bonnet, which lifts to create added space for deformation, thereby substantially reducing the risk of injury to pedestrians. The active bonnet system comprises three impact sensors in the front section of the car and special bonnet hinges which are pretensioned and locked into place with strong springs. The sensors signal a collision with a pedestrian to the electronic control unit, which immediately activates two electromagnets in the hinges. These electromagnets release the lock, allowing the spring action to raise the rear of the bonnet by 50 mm. This whole process takes only a fraction of a second.