Research On Speed Identification Of Car To Two Wheelers Automobile Accident

In recent years,the four indexes of road traffic accident declined year by year in China,but a slight upward trend in car to two wheelers automobile accident.Car to two wheelers automobile accident is particularly common in two wheelers automobile accident.Speed identification is the core of car to two wheelers automobile accident reconstruction,and the objective and science of the result is very important.In this paper,the research of the still positional relationship among the accident participants,the sensitivity of the parameters related to the accident site and rider injury is carried out.In order to evaluate the impacted velocity and the impacted position for reconstructing a car to two wheelers automobile accident with an unknown impacted position,first designed the simulation experiment and verified the simulation data,then,the relationship between the impacted velocity and distance between rest positions of the car and the two wheelers automobile,that of the car and the rider,and that of the two wheelers automobile and the rider was obtained by random forest and simulation data by Pc-Crash;the relationship between the braking distance of the car and those three distances was obtained based on those same data and same method.Finally,demonstrated and validated the model by two real cases,the results showed that the speed got by model is very close to the others.In order to collect trace information closely related to speed identification in car to two wheelers automobile accidents,first got 17 sensitive parameters required immediate attention and related to collision speed through theoretical analysis,then,a method based on random forest model for analyzing the sensitivity of these parameters was proposed and the range of each parameter was defined,finally,based on the random forest model make 17 sensitive parameters in order,the results showed that the car braking distance,the thrown distance of cyclists and pedestrians are most significant among 17 sensitive parameters related to collision speed.Finally,based on the results of parameter sensitivity analysis combined with the speed identification,an information collection form was drew of car to two wheelers automobile collision accident.To make full use of rider injury information associated with the speed identification,first got simulation data by PC-Crash and got key impact factor of different rider injury site by random forest,the results showed that the greatest influence on the chest and head injuries are speed;knees and left legs are collision angle;the right shank is the friction coefficient between two wheelers automobile and the ground;the femur is the friction coefficient between human body and the ground,then,the quantitative relationship was obtained between head injury and speed by the in-depth analysis;the quantitative relationship was obtained based on those same data between chest injury and speed.Finally,verified the simulation results based on the quantitative relationship through a real case.The research showed that the still positional relationship among the accident participants,the sensitivity of the parameters related to the accident site and rider injury provided the method for speed identification.Furthermore,it is significant to improve the level of road traffic accident reconstruction.