Pedestrian protection has come up to an important issue. The European Community (EC) has released a draft law, which mandates manufacturers to increase pedestrian safety. This law consists of two phases, beginning in 2005 and 2010 respectively. To face up with present and future challenges, the Bosch roadmap of Electronic Pedestrian Protection (EPP) provides three sensor system generations:​ a contact sensor system (EPP1), a system combining contact sensors and ultrasonic sensors (EPP2) and a system combining ultrasonic sensors and video sensors (EPP3). In this paper, we focus on EPP2 and EPP3.

EPP2 uses synergy effects with ultrasonic systems (e.g. the parking aid) that are well-established on the market, in order to enhance the classification performance. In the EPP2 system, the ultrasonic sensor subsystem generates a feature vector which carries ultrasonic as well as geometric properties. This feature vector is combined with that of the contact sensor subsystem, which gives information about the mechanical object properties "stiffness" and "impact energy" of the object. The combination of the feature vectors leads to an improved and robust classification, allowing the use of an irreversible actuator.

In the EPP3 system, the video subsystem accomplishes pedestrian recognition in a mid-range ahead of the car and, if necessary, initiates a driver warning (acoustic, optical). Video-based pedestrian recognition is achieved by contour analysis, while tracking of pedestrians is carried out by applying an extended Kalman filter to active-shape represent- tations of pedestrian contours. Any time the video subsystem predicts a pedestrian to enter the ultraso- nic field-of-view, information concerning direction of movement and velocity of the respective pedestrian plus an estimate of the time-to-impact is transferred from the video subsystem to the ultrasonic subsystem. The main task of the ultrasonic subsystem is to verify or reject the hypo- thesis of pedestrian presence delivered by the video subsystem.