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Bumpers have lost their important functions of crash load isolation and inter-vehicle compatibility. Occupant compartment protection has been shifted to collapse of surrounding structures, with vehicle inoperability and occupant injury not unusual after a 50 km/h barrier impact. For higher speed vehicle and occupant survivability, a larger crash stopping distance is needed - provided by bumpers extended by radar sensing of need just before the crash. The hydraulic extended bumper was first developed by Professor James Ryan, giving vehicle driveability after a 40 km/h barrier crash, and further developed worldwide in the Experimental Safety vehicle programs, but unfortunately never developed for the commercial market. Our current work is to demonstrate the potential of compartmented airbag bumper systems inflated just before the crash to cover 1 square meter on the crash surface.

A frontal barrier crash at 48.5 km/h and a moving rigid barrier crash at 48.5 km/h into the side of a stationary car have been carried out at the Insurance Institute for Highway Safety's Vehicle Research Center, with the car having frontal then side preinflated airbag bumpers. This is a preliminary simulation of an airbag bumper system with the needed airbag inflation triggered by radar sensing of the approaching threat. The frontal airbag bumper had a high pressure airbag at 221 kPa and 23 cm thick imbedded on the outboard side of a low pressure airbag at 20 kPa whose inboard side was against the original car bumper, with a thickness of an additional 61 cm at the center line, for a combined thickness of this prototype airbag bumper of 84 cm. The low pressure airbag ruptured as expected in the frontal crash, with the airbag bumper absorbing about 19 percent of the energy of the crash due to excessive penetration into frontal structures.