The active safety systems, for instance cameras and ultrasound sensors, are of the highest standard in today’s vehicles. In the event of an unavoidable accident there is only a fraction of a second to spare.
When the safety electronics register a crash, the passive systems, such as seat belt tensioners and air bags, must be triggered in a few milliseconds. The systems must be perfectly coordinated to offer the passenger the best possible protection
Electric vehicle vs. conventional drive
The change from slight to long delay presents new challenges to us in the design of passive safety systems
Based on this information and in consideration of the deformation behaviour of an electric car, Kai and Valentin coordinate the trigger time of seatbelt tensioners and air bags to each other. The interaction of both systems must be perfectly harmonised. In the first ignition threshold the seatbelt tensioner is first triggered and shortly after that the air bag. Some air bags have additional levels’, according to Kai. In addition the air bags must be correspondingly softer or harder, depending on the dimensions of the passenger, to provide the best possible protection. For instance, the air bag must be softer for a smaller woman than for a large man.
The different legal framework conditions posed a further legal challenge. Kai and Valentin must ensure that the design conforms to specific guidelines. For instance only limited forces may act on some body regions, which are specified in kilonewtons. These guidelines vary from market to market, which the engineers must consider during the development.