A concept for a car seat offering enhanced safety has been developed and test models have been built. Although this seat has been designed for the harder conditions in low mass vehicle collisions, the concept can easily be adapted to conventional cars. The seat features an automatically controlled head restraint adjustment mechanism which guarantees a small and relatively well defined distance between the occupant's head and the head restraint. Based on computer simulations, paddings for the different regions of the seat back and an energy absorbing yielding mechanism of the seat back have been designed in such a way that only little relative displacements in the head-neck-thorax system, reducing the risk of cervical column injuries, are to be expected even during a severe rear-end impact. Different occupant sizes ranging from the 5th percentile female to the 95th percentile male have been considered. A series of rear-impact sled tests with velocity changes from 12.2 to 38.6 km/h and acceleration levels from 6 to 30 g has been performed using a 50 percentile Hybrid III dummy equipped with the new TRID neck. The measurements show a good correlation with the simulation and the risk of cervical column injuries is considered to be substantially lower than in conventional seats.
Abstract