A new seat slide was developed to prevent whiplash injury. The behaviour of the seat during low-speed rear-end impacts is improved. All functions as well as the behaviour of the seat in other impact conditions remain unchanged.
The system consists of a damping mechanism which is triggered by a sensor. A certain vehicle acceleration followed by an impact force extended by the occupant on the seat back is needed to activate the system. Unintended activation is prevented. Once the system is activated, the seat is allowed to move backwards in a purely translational manner while the motion is damped. A distance of approx. 40 mm can effectively reduce the occupant neck loading.
Sled test experiments were performed to analyse the behaviour of the new system. The tests were conducted to mimic rear-end collisions with a delta-v of 16 km/h. A BioRID dummy was used as a human surrogate. The results indicate the beneficial influence of the damping seat slide on the occupant kinematics. In particular the so-called S-shape deformation of the neck assessed by the neck injury criterion NICmax is reduced. Comparing a standard car seat with and without the damping seat slide, it was shown that the NICmax is reduced by approx. 40%.
Hence it was shown that besides the head restraint and the recliner that are used in other whiplash protection systems, also the seat slide has the potential to prevent whiplash injury.