Improving pedestrian safety using numerical human models

Pedestrian accidents are one of the main causes of traffic fatalities and injuries worldwide. New pedestrian safety regulations are being proposed in Europe and Japan to improve the protection afforded to pedestrians. Numerical simulations with biofidelic pedestrian models can be used to efficiently assess the risk to injury in pedestrian-vehicle impacts and to optimize the pedestrian protection in the early stages of the vehicle design process at relatively low costs. The goal of this study was to develop and validate a scaleable mid-size male pedestrian model. The model parameters were derived from published data and a large range of impactor tests. The biofidelity of the model has been verified using a range of full pedestrian-vehicle impact tests with a large range in body sizes (16 male, 2 female, height 160-192 cm, weight 53.5-90 kg). The simulation results were objectively correlated to the experimental data. Overall, the model predicted the measured response well. In particular the head kinematics were accurately predicted, indicated by global correlation scores over 90 %. The correlation score for the bumper forces and accelerations of various body parts was lower (47-64 %), which was largely attributed to the limited information available on the vehicle contact characteristics (stiffness, damping, deformation). Also, the effects of the large range in published leg fracture tolerances on the predicted risk to leg fracture by the pedestrian model were analyzed in detail. The validated mid-size male model was scaled to a range of body sizes, including children and females.