A car with reflexes?

Motor,  Apr 2003  by Nash, Tom

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The 2003 Mercedes-Benz S-- Class sedan is the world's first production car equipped with a new high-- tech system that can sense a possible collision a few seconds in advance and take protective measures. The innovative system-called Pre-Safe-first tensions the seat belts if it senses an impending collision. The system uses new resettable electric tensioners in addition to the existing pyrotechnic belt tensioners that still deploy on impact.

If the front passenger seat and any of the electrically adjustable rear seats are reclined, Pre-Safe moves them to a more vertical position and, if the vehicle skids (sometimes a precursor to rollover), the system automatically closes the sunroof. If a crash is averted, the electric belt tensioners automatically relax and are ready to deploy again, if necessary.

Pre-Safe reacts to uncorrected fishtailing as well as "plowing" by using existing ESP stability control sensors to measure steering angle, vehicle yaw and lateral acceleration. Emergency braking can also trigger Pre-Safe, which monitors sensors for the Brake Assist system, as well.

Mercedes-Benz accident researchers found that about two-thirds of all accidents are preceded by skidding, emergency braking or a sudden evasive maneuver-all of which can provide several valuable seconds of advance warning before impact. In the past, the auto industry didn't make use of this relatively wide and potentially lifesaving "window," since conventional air bags and seat belt tensioners are triggered only on actual impact. However, Pre-- Safe makes use of technology that reads these danger signals in advance and uses the remaining seconds to react and take some precautionary measures. Just as the perception of sudden danger triggers a human reflex action, Pre-Safe triggers special systems to reduce the risk of occupant injury.

Copyright Hearst Business Publishing Apr 2003
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