ZF live demonstrated the world’s first pre-crash occupant safety system with an external side airbag in Memmingen. “We highlighted that this safety system has the potential to significantly reduce occupant injury severity in cases of side impact collisions,” explains Uwe Class, Head of the safe Mobility Systems department, within ZF’s Advanced Engineering team.
The development of this system had a big challenge of reliably recognizing an unavoidable collision and deploying the external side airbag before the collision takes place. The system has approximately 150 milliseconds to make the decision to deploy the airbag and fill it – roughly the amount of time it takes a person to blink.
The sensors of the vehicle first have to identify a potential impact quickly and accurately. The connected cameras, radar and lidar makes this possible. Algorithms within the system software decide whether or not a collision is unavoidable and the deployment of the airbag is both possible and beneficial. If these decisions are all positive, the system ignites the airbag inflators to fill the airbag. The airbag, which has a capacity of between 280 and 400 liters (five to eight times the volume of a driver airbag) depending on the vehicle, then expands upwards from the side sill to form an additional crumple zone in the door area between the A and C pillar.
The predictive information about an unavoidable collision helps to further improve the effectiveness of established standard safety technology. For example, the ACR8 Active Control Retractor can warn the occupants or help secure them in a safe position in the critical fractions of a second before the collision.