1. Field of the Invention
The present invention relates to systems and methods for reducing injury to occupants during a side impact collision. More specifically, the present invention relates to displacing vehicle occupants away from and reinforcing the vehicle against intrusion in side impacts.
2. Description of Related Art
The inclusion of inflatable safety restraint devices, or airbags, is now a legal requirement for many new vehicles. Airbags are typically installed in the steering wheel and in the dashboard on the passenger side of a car. Additionally, airbags may be installed to inflate beside the passenger to provide side impact protection, in front of the knees to protect the knees from impact, or at other strategic locations.
Despite the development of side airbags, problems still remain in the area of side impact protection. For instance, insufficient space for side airbags to decelerate and cushion vehicle occupants is a continuing problem. Additional problems with side impact protection include the lack of strength in the vehicle sidewall, the close proximity of an occupant to the impact zone, and the higher likelihood of intrusion by the impacting vehicle into the occupant compartment of the vehicle.
These problems are compounded by differences in vehicle characteristics between the impacting vehicle and the target vehicle. Some of these characteristics include weight differences, geometry differences, differences in stiffness, and particularly differences in height off the ground. Vehicle compatibility becomes a concern when the impacting vehicle and the target vehicle are mismatched, for instance, when a larger SUV (sport utility vehicle, light truck, or van) impacts a smaller compact car.
In a mismatched collision, the smaller target vehicle undergoes a higher velocity change, and has less structure to absorb the impact energy. In a mismatched side impact, the larger striking vehicle is elevated with respect to the smaller target vehicle causing the brunt of the impact to be absorbed by the passenger compartment of the target vehicle, rather than striking the target vehicle's horizontal base member, or sill.
Since the side of the passenger compartment is often less stiff than the striking car's front, the side of the target vehicle is deformed into the passenger compartment. The smaller target vehicle potentially has less interior space to mitigate this effect of intrusion into the passenger compartment and the impact of the striking vehicle can hit the occupant of the target vehicle at speeds approximating the initial speed of the striking vehicle. The occupants of the target vehicle are severely endangered thereby.
A recent analysis of crash data reveals that larger SUV-to-car collisions produce a significantly higher rate of fatalities than car-to-car collisions. For example, when SUVs strike passenger cars on the left side, the risk of death to the car driver is five times higher than the risk associated with a car-to-car left side impact collision. The recent increase in the percentage and number of larger vehicles, such as SUVs, currently operating has exacerbated this problem.
To counteract these problems, some vehicle protection systems have been developed to move the occupant and increase the distance between the occupant and the vehicle sidewall. These systems include moving the occupant laterally or tilting the seat away from the impact area.
However, these methods have not fully solved the problems described above. For instance, many vehicles have a hump in the middle of the vehicle that prohibits lateral motion. Tilting the seat accelerates the occupant's head toward the middle of the vehicle, which acceleration may injure the occupant. In addition, neither method protects the occupant against intrusion into the occupant compartment of the vehicle. Neither method provides an answer to the increased risks associated with a high profile vehicle impacting a low profile vehicle.