Recent legislation has increased the type approval requirements in the domain of pedestrian protection. A non design restrictive solution for the bonnet area is the implementation of pop-up bonnet systems. Obviously, such systems need a sensing element detecting and classifying the impact object in order to make a fire/no-fire decision for the bonnet lifting actuators.

The working principle of IEE’s pedestrian protection sensor system not only allows the detection of pedestrian-type impacts, but also analyses crash event scenarios. Thus the same sensor is not only used for pedestrian protection, but can also contribute to passive safety by delivering information that can be used for enhanced occupant safety. In decision-making for the pop-up bonnet deployment, it is crucial to reliably distinguish between pedestrians and other objects like traffic signs, footballs or small animals, whereas in crash sensing, it is helpful to know as early as possible whether the collision object is a tree or a vehicle.

The pressure sensitive sensor is integrated into the vehicle front-end and detects parameters like T0 (first contact), impact location, width of impacting object and impact dynamics. These data allow a more precise tuning of the restraint systems to specific crash events, the usage of less aggressive restraint systems due to the early T0 signal, as well as the replacement of existing sensors (upfront, pole catchers, redundancy).

The sensors ability to deliver robust data in frontal crashes has been demonstrated in tests reflecting compliance, consumer and insurance testing requirements.

In order to provide even more information about crash situations and to offer optimised and costeffective solutions for other applications, the goal is to develop a family of general impact sensors also covering the detection of rear-end collisions and side impacts.