F2008-08-112
Assessment of Integrated Pedestrian Safety Systems
A few years ago vehicle safety was all about occupant protection. Huge efforts have been made in the last decades to increase road safety. Therefore, modern cars are unprecedentedly safe in terms of occupant safety. Consequently, there is still a great potential to save the lives of vulnerable road users and to minimize their injuries. Legislation has been set up in Europe and Japan to test the passive pedestrian safety features of new vehicles. Against the background of the development of advanced driver assistant systems, the European pedestrian safety approach has to be adapted. These active safety systems might be able to sense an upcoming unavoidable collision prior to first contact and reduce its severity, or even avoid a crash by using advanced warning and driver assistance strategies.
The exact potential of combined active and passive safety measures for injury risk mitigation can be evaluated by the VERPS+ index which has been developed. An evaluation of the influence of collision speed on the risk for severe head injuries allows the exact prediction of safety benefits of brake assist systems, which depends on vehicle specific properties, driving behavior and accident scenarios. A group of drivers has been evaluated in order to verify the wide range of possible human interaction in emergency brake situations. A virtual vehicle model has been set up to evaluate future driver assistance strategies in accident situations derived from In-Depth accident analysis. To analyze the safety impact of advanced driver assistance strategies, driver data of braking behavior and valid simulation of vehicle dynamics are used to perform a statistic analysis of accident prevention and mitigation potentials.
Basically, advanced driver assistance systems prevent or mitigate accidents, thus minimizing pedestrian injury risks. It can be shown, that passive and active pedestrian protection measures complement each other nearly ideally, while the injury mitigation potentials of structural measures alone remain limited and cannot address the secondary impact of the pedestrian on the road. The additional introduction of brake assistance systems is equivalent to the protection potential of additional structural measures (active or passive).
It has been shown that fully autonomous emergency braking maneuvers and intelligent speed management systems are limited regarding their pedestrian protection potential. Keeping the driver in the loop and adapting driver assistance strategies so that the driver always maintains driving responsibility ensures customer acceptance and product liability concerns.
For the evaluation of possible political options to regulate pedestrian protection legislation, it is important to weigh costs and benefits against each other. It is important what kind of brake assist systems - dependent on the stage of development - with relatively small additional expenditure can be realized. The comparison of different pedestrian protection measures offers the possibility of identifying the most efficient measures for the examined vehicle and to maximize real-life safety benefit by reasonable combination of active and passive safety features.
Session: Occupant & Pedestrian Protection II