Research On Pedestrian's Kinematics And Injury Pattern After Collision Based On Real Pedestrian-vehicle Accident Data

Vehicle-pedestrian mixed traffic condition is serious in China,pedestrians always occupy a higher proportion of casualties in traffic accidents,so pedestrian collision safety has become a hot issue in the field of passive safety.In this paper,based on the data of real vehicle-pedestrian accidents,the distribution of initial collision parameters as well as the pedestrian's kinematics and injury parameters after the collision are studied.The influence of initial collision parameters on the movement and injury parameters after collision is systematically studied.Based on the Madymo platform,a facet vehicle model suitable for vehicle-pedestrian collision research is established,which is validated by the relevant experimental data.Secondary development is conducted based on the facet human model originally established by the University of Virginia,an optimization method is applied to improve the mechanical properties of the neck model,and the bio-fidelity of the human model is validated.A simulation model of vehicle-pedestrian collision is further established,which is validated by the reconstruction of a real vehicle-pedestrian accident,the simulation model lays the foundation for the follow-up Monte-Carlo simulations.Meanwhile,the model can also lay an important foundation for the practice of vehicle-pedestrian accident reconstruction.Based on the typical vehicle-pedestrian accident data from the traffic accident database of Tsinghua University,the statistical distribution of the initial collision parameters is obtained by statistical analysis,which will be used as the basis for generating random numbers of the initial collision parameters.On this basis,a total of 2660 vehicle-pedestrian collision tests are carried out using the Monte Carlo method.The statistical distribution of the kinematics and injury parameters after the collisions is systematically studied.The probability distribution model of the kinematics and injury parameters after the collisions is established.The model can be used to provide head collision condition from the real accident data to the research related to energy-absorption characteristics of hood and windshield.It also provides important data support for the development and design of the pedestrian airbag and pop-up hood.By parameterization method and statistical nonparametric test method,the coupling influence of vehicle collision speed and other initial collision parameters on pedestrian motion and injury parameters are systematically studied.A confidence interval model with confidence level 0.90 and pedestrian injury risk prediction model are established.Finally,a multivariate regression model that can describe the relationship between initial parameters of collisions and pedestrian injury indicators is established.The above models reveal the changing rules of pedestrian kinematics and injury parameters under the influence of initial collision parametersin pedestrian-vehicle accidents,which can provide theoretical reference for the identification of pedestrian-vehicle accidents.Active,passive and active-passive integrated protection countermeasures are introduced to further Monte Carlo simulations.The effectiveness of active,passive and integrated active-passive protective countermeasures for pedestrian protection under Chinese traffic condition are predicted and comparative studied,as well as the influence of collision speed to the protection effectiveness of active,passive and active-passive protective measures.It provides theoretical support for the feasibility of active-passive integrated protection system under Chinese traffic conditions.