Research On Reconstruction Of Pedestrian-vehicle Collision Accident And Vehicle Speed Calculation Based On Throw Distance And Injury

With the increase of car ownership year by year,road traffic accidents occur frequently in China.When dealing with pedestrian-vehicle collision accidents,the accuracy of the vehicle speed identification of the accident is crucial to the division of accident responsibility and the resolution of accident disputes.However,the traditional accident reconstruction method cannot satisfy the accuracy and efficiency of the vehicle accident speed identification.Based on this,thesis systematically studies the rules of pedestrian throwing distance,damage and collision speed,and aims to propose a reliable and efficient method for calculating the vehicle speed of an accident.Firstly,based on the analysis of the reconstruction theory of pedestrian-vehicle collision accident,the evaluation indexes of pedestrian throw distance suitable for pedestrian-vehicle collision accident research are established: horizontal throw distance,longitudinal throw distance,total throw distance,throw distance of the first landing place;pedestrian injury evaluation indexes: head HIC value,chest 3ms acceleration,leg shear force.Thesis combs the application scope,advantages and disadvantages of several speed calculation methods commonly used in pedestrian-vehicle collision accidents.Secondly,based on NAIS data,the vehicle type,collision vehicle speed,collision location,pedestrian height,pedestrian pace,pedestrian emergency posture and other factors are selected as the initial collision parameters;PC-CRASH and MADYMO multi rigid body simulation models of pedestrian-vehicle collision are constructed,and the accuracy of the simulation model is improved by optimizing the parameters of vehicle and pedestrian models.On this basis,using PC-CRASH and single factor analysis method to carry out 500pedestrian-vehicle collision simulation tests.The pedestrian throw distance and collision vehicle speed under different initial collision parameters are obtained,and three typical throwing motion forms are proposed: winding type,jacking type and arching type,which provide accurate pedestrian trajectory information for accident reconstruction research.Thirdly,on the basis of PC-CRASH simulation,500 pedestrian-vehicle collision simulation tests are carried out by using MADYMO,and the pedestrian injury and collision vehicle speed laws under different initial collision parameters are obtained,which reveals the significant relationship between pedestrian injury and collision vehicle speed,and provides ideas for accident reconstruction research.The safety speed standards are put forward:65km/h(car),62km/h(SUV),55km/h(van),which provide the basis for the speed limit law based on pedestrian protection.Finally,thesis uses the established pedestrian-vehicle collision model,combined with the rules of pedestrian throw distance and pedestrian injury,to reconstruct 20 real cases of car-pedestrian collisions,and establishes the vehicle speed calculation mode based on pedestrian throw distance and injury parameters through regression analysis.The model of vehicle speed calculation proposed in thesis is verified by MATLAB and classic throw distance model.The results show that the model of vehicle speed calculation proposed in thesis can improve the accuracy and efficiency of accident identification work,and can be used as a reference for accident identification workers.