ZF has been looking into the impact external airbags could make on car accident injury rates. Turns out, it's potentially huge.
According to the company, its prototype external side airbag could lessen occupant injury severity by a whopping 30 per cent in perpendicular crashes.
Obviously, ZF hasn't just strapped a heap of steering wheel inflators on the side of a car. The test unit has a 250L volume, making it three times the size of a regular curtain airbag.
The concept designs use the same materials and inflator technology as current interior airbags, however. The unit is more than 300mm thick in some places, with the majority of reinforcement focused on a vehicle's stiff impact structures – door pillars, for example.
“The lack of deformation space means cars can be more vulnerable to side impact,” said Swen Schaub, senior engineering strategy manager at ZF.
“The airbag is designed to deploy in the last moment before a collision. As it deploys, it opens upwards, staying close to the structure to help cover the doors and pillars at the side of the car.”
To make sure the unit actually inflates correctly, ZF says cars will need to be capable of detecting an accident before it happens. Around 100 milliseconds is the latency, meaning cars will need to rely on radar, Lidar or camera sensors if the airbag is to work correctly.
The airbag needs to be inflated fully before impact if it's to work effectively.
“The system requires the ability to predict both impact direction and location,” said Schaub. “And it needs to do this in a timely manner, as even a small vehicle movement in the final 500 milliseconds before the impact could make a significant difference.”