Research On The Vehicle Velocity Calculation Method Of Three-Dimensional Collision In Road Traffic Accidents

At present,China's road traffic safety situation is still grim,frequent accidents and high death rate are two major problems in our country.For the fair division of responsibility,scientific analysis of causes of accidents,it is often necessary to identify the vehicle speed at the time of the accident.As the most complex form of collision,vehicle three-dimensional collision is difficult to reproduce,and the accuracy of reproduce results is poor.Therefore,it is of great practical significance and social value to research the method of calculating the three-dimensional collision velocity in road traffic accidents.Firstly,this paper analyzes the process of vehicle rollover accident,uses Pc-Crash software to simulate curve rollover accident.After verification,the result shows that the vehicle rollover or jump formula is more in line with the Trip Phase and Post-Trip Phase.In addition,a method for calculating the speed of vehicle rollover accident is put forward under the condition that the slip mark radius is unknown.Secondly,according to the law of conservation of momentum,a simplified algorithm of vehicle speed is established for vehicle two-dimensional collision and three-dimensional collision.By introducing the road traffic accident reconstruction software Pc-Crash,the paper proposes a method of vehicle speed reconstruction based on simplified algorithm and Pc-Crash,and the two-dimensional collision and three-dimensional collision accident cases are reproduced and analyzed.Finally,the uncertainty theory is introduced,the vehicle speed calculation method based on uncertainty theory is proposed,and it is applied to three kinds of vehicle speed theoretical calculation methods,include the law of conservation of momentum,the kinetic energy theorem and the projectile model.This method is used to evaluate the two-dimensional collision and three-dimensional collision accident cases,and the results are compared with the results of Pc-Crash software.Based on the analysis of vehicle rollover accident and vehicle two-dimensional collision accident,the method of vehicle speed reconstruction based on simplified algorithm and Pc-Crash and the vehicle speed calculation method based on uncertainty theory are proposed for the vehicle three-dimensional collision accident.The validity and correctness of the methods are verified by practical accidents.