Study On The Method Of Vehicle Speed Calculation In Pedestrian-Vehicle Crash

Pedestrians are vulnerable groups in traffic accidents, in the 2008 to 2013 years, the death toll in the vehicle-pedestrian collisions occupies 26% for all traffic accidents, it's average 32 people died per a hundred vehicle-pedestrian collision, the death rate is much higher than other types of traffic accidents. Therefore, in human vehicle accident treatment,traffic police department has paid more and more attention to identification of correlation of the collision speed calculation, injury of pedestrian, vehicle deformation, final state of pedestrian and cars and other results, with accidents of pedestrians, vehicles, road, which demands for the analysis and identification is also getting higher and higher. It is necessary to improve the accuracy and efficiency of traffic accident speed identification, and further study on vehicle speed prediction and process simulation by use of injury, vehicle traces of collision,vehicle and pedestrian eventually stop state accidents inquest information.This paper briefly discussed pedestrian-vehicle collision accident analysis technology research status at home and abroad, the accident investigation methods and status, compared accident information collection and in-depth investigation project and characteristics of traces of pedestrian-car accident.In order to study influence of the aspects of human, vehicle, road on the vehicle-pedestrian collisions, we study on the significant of influence of hood edge height,bumper bottom height, hood length, human height, human weight, vehicle speed, impact angle, impact position, pedestrian speed, friction coefficient between pedestrian and vehicle,friction coefficient between pedestrian and ground,friction coefficient between vehicle and ground by orthogonal experiment and PC-CRASH simulation software on the distance between the last position of vehicle and pedestrian. As a result, the significant factors is speed and hood edge height, and secondary significant factors is hood length, human height and impact angle. And a real case is used to adjust the collision model, it is feasible to establish and adjust the collision model of the human vehicle according to the significant factors.Using MADYMO simulation software to build a vehicle collision model and study on the influence of speed, hood length, front height, hood edge height and impact angle of distance between the last position of vehicle and pedestrian, envelope length and pedestrian head HIC. As the result: the distance decreases with human height and hood length increases,and increases with the increase of speed, hood edge height and impact angle. The length of the envelope is increased with the increase of the velocity and human height, and decreases with the increase of hood length and hood edge height. The impact angle has little influence on the envelope. HIC increases with the increase of vehicle speed, and decreases with the increase of hood length, hood edge height, pedestrian height and impact angle.By use of SPSS statistical software for statistical analysis of simulation data, obtain two multivariate linear regression prediction model, it analyzed the relationship between vehiclespeed and eventually stop relative distance, pedestrian height, impact angle, hood height,hood length, the other model is the relationship between speed and envelope line length,pedestrian height, hood height, hood length, then through 3 a real case to verify the practicability of the two regression equations. It is feasible to calculate the vehicle collision speed by regression prediction formula. The prediction model can be used for the rapid estimation of vehicle speed in traffic accident vehicle speed identification.