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. The airbags would be inflated to extend out 0.6 m on the front, or 0.3 m on the rear or either side, or 0.15 m on the roof. The airbags could sustain up to 700 kilopascals peak loads when compressed. In a frontal crash, this is enough to decelerate a 1300 kg car at -25 Gx peak and remove 40 km/h equivalent energy from the crash event, leaving collapse of the hood, trunk, or doors for higher speed survivability. Preliminary swing crash tests are presented, along with a discussion of needed car load path changes.