ZF
gave a live demonstration of the prototype for 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.
ZF
is currently the only company to provide the full spectrum of integrated
vehicle safety technology – from sensor systems, algorithms, and control units
to active and passive actuators. “Our deep understanding of the entire ’see.
think. act.’ process enables us to conceptualize and realize integrated vehicle
safety solutions such as the new pre-crash safety system,” says Class.
From Recognition to Deployment in the Blink
of an Eye
The
biggest challenge in the development of this system was 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
vehicle’s sensors first have to identify a potential impact quickly and
accurately. This is possible with connected cameras, radar and lidar.
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 affirmative, the system ignites the 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 pillars.
Reduce the Risk of Injury
In
a side impact collision, the occupants on the side of the impact are at
particular risk of serious injuries in the chest area if the passenger cabin is
severely deformed. The ZF pre-crash safety system can reduce the penetration of
the intruding vehicle by up to 30 percent, helping to significantly reduce the
occupants’ risk of injury.
The
predictive information about an unavoidable collision also 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.