Smart fender recognises pedestrian impact
An impact sensor for cars that can instantly recognise and protect pedestrians in an accident has been developed by engineers in Germany.So you’re telling me that I can get struck a car equipped with this going, oh, about 60 miles and hour and say “My, what a friendly bumper!”? Huh. Well, if it saves just one life it’s done it’s job.If the sensor detects that a pedestrian has been struck, the hood (bonnet) of the car is immediately pushed a few centimetres upwards by a system of hydraulics. This creates a vital buffer zone between the pedestrian and the car’s suspension turrets and engine block. Crash tests have shown this buffer can prevent a pedestrian receiving a serious head injury on impact.
To prevent false alarms popping up the hood, the system distinguishes between pedestrians and other objects on the basis of their mass. It can differentiate the mass of a small child and that of a traffic cone, says Johannes Vetter of Siemens Restraint Systems, the company behind the design.
The key to the system is a set of mirror-coated fibre optics in the car’s fender (bumper). These are broken on impact, meaning that light that leaks out, and the amount of light detected by a sensor at one end decreases. An onboard computer uses this loss and the vehicle’s velocity to calculate the mass of the obstacle struck.
