According to the company, the system which only works for side impact crashes, can help save lives and reduce occupant injury severity by up to 40%. In Germany alone, they account for nearly 700 deaths per year, nearly a third of all occupant fatalities.
Up to 30% of the force of the offending vehicle could be reduced by the external side airbag which is deployed milliseconds before a collision to provide an additional lateral crumple zone.
ZF did not detail how it works but said that the external airbags can communicate with the car's radar, cameras sensor systems. They “developed algorithms that are capable of determining if a crash is imminent and decide whether or not to deploy the airbag.”
Challenges faced by the ZF include the programming of the system to reliably recognize an unavoidable collision and deploy the external side airbag before the collision takes place. The other issue it faced was that the airbag has a capacity of between 280 and 400 liters, five to eight times the volume of a driver airbag making it harder to fill up fast enough.