Analysis of test tools for evaluation of contact-based sensor systems for pedestrian detection

Abstract

Active systems of the passive vehicle safety, like deployable bonnets or external airbags, are installed in series vehicles since 2005 to fulfil pedestrian protection requirements. However, an appropriate test procedure for these systems was not available until 2010, when Euro NCAP published a revised version of the pedestrian test protocol (version 5.2). In this test protocol, a test method to evaluate contact-based sensor systems for pedestrian detection using so-called hardest-to-detect impactors is described. These impactors shall reproduce the lowest possible impact load induced in the vehicle front in case of a collision with a pedestrian, which is strongly dependent on the anthropometry of the pedestrian as well as the impact configuration. In this paper a holistic analysis of the accident kinematics of pedestrian–vehicle collisions and resulting loads induced in the vehicle front is conducted. The vehicle front is modelled using a generic vehicle buck, which is specifically designed for this analysis. As can be observed by the conducted simulations, the pedestrian size inducing the lowest possible impact load varies for different vehicle categories. Thus, it is not sufficient to consider only one pedestrian size. The comparison of these vehicle–pedestrian simulations with the loads being induced by three hardest-to-detect impactors shows that none of the three impactors is able to reproduce the ‘worst-case scenario’ for all analysed four vehicle categories. The results of this study, which was conducted on behalf of and funded by the German Federal Highway Research Institute (BASt), could be used for the development of a suitable, effective and objective test procedure for active systems of the passive vehicle safety with regard to pedestrian protection.