Bumper bag for SUV to passenger vehicle compatibility and pedestrian protection

An external airbag (bumper bag) for improved sport utility vehicle (SUV) to passenger vehicle compatibility in side impact and improved pedestrian protection was developed. The bag was developed and evaluated by means of mathematical simulations and mechanical crash tests. The mounting location of the bumper bag was below the bumper structure of an SUV. The volume of the bag was 134 liters and the peak pressure of the bag when loaded was approximately 7 bars. In the mechanical crash tests a Ford Explorer with and without a bumper bag was run into the side of a Toyota Corolla. The impact angle was 90 degrees and the impact velocity was 48 kph (30 mph). It was found that the bumper airbag significantly reduced the b-pillar peak intrusion velocities and maximum deformation of the impacted vehicle. The potential injury reducing benefits for a pedestrian impacted by an SUV equipped with a bumper bag was also evaluated. Using a pedestrian leg form both impact and inadvertent firing tests were carried out. In the impact test the leg form was impacting the front of the Ford Explorer at 40 kph (25 mph) with and without bumper airbag. In the inadvertent firing tests the leg form was positioned in contact with the bumper of the SUV when inflation of the bumper bag was initiated. It was found that the bumper bag reduced the knee bending angle, shear displacement and tibia acceleration significantly. All injury measures but one was below the European New Car Assessment Program (EuroNCAP) injury assessment values for the lower extremity. The potential reduction in injury measures for an occupant on the impacted side of the passenger car impacted by an SUV with a bumper airbag was evaluated. The evaluation was carried out by means of sled tests. The intrusion velocities at the chest level of the impacted vehicle in the crash tests were used to drive the sled in sled tests. In the sled tests a state of the art occupant protection system was used. The system comprised a seat belt system and a side airbag. It was found that chest injury measures were significantly reduced when a bumper bag was used in a SUV to passenger vehicle side impact. Future development of the bumper airbag system will include improved frontal impact compatibility and self protection.