In a live demonstration, ZF has presented the prototype of what it claims to be the world’s first pre-crash occupant protection system with external side airbag. For this purpose, the company networked the airbags with the vehicle’s environment sensors. Algorithms can determine whether a crash is imminent and decide whether the airbag should be triggered or not.
The biggest development challenge: Even before the collision of the opponent, the system must be able to detect an unavoidable accident beyond any doubt and trigger the external side airbag reliably. The system only has about 150 milliseconds to decide, ignite and fill the airbag.
First of all, the vehicle’s environment sensors must quickly and precisely identify possible dangers. The camera, lidar and radar all work together to achieve this. Algorithms then define whether the impact is unavoidable and whether it is possible and advantageous to trigger the airbag. If so, gas generators ignite and fill the airbag. Depending on the vehicle, the airbag is 280 to 400 litres in size – five to eight times the volume of a driver’s airbag – and unfolds upwards from the side skirts: It thus forms the additional crumple zone in the door area between the A and C pillars.
In the event of a side collision, the occupants on the side facing the accident are particularly at risk in the chest area if the opponent strongly pushes the passenger cell. ZF’s pre-crash protection system can reduce the penetration of the opponent into the body by up to 30 percent, thus significantly reducing the risk of injury to the occupants.