Research On Trajectory Reconstraction Model Of The Vehicle In Two-Dimension Collision Accidents

With the rapid development of the global economy, the amount of automobile is increasing rapidly, and the problem of road traffic safety is more and more prominent. Studies indicate that the number of vehicle collision accident is more than half of the gross number of road traffic accident, and which has threatened to our life and property safety. Moreover, two-dimension collision accident is one of the most familiar accident modality of vehicle collision accident. The trajectory reconstruction of vehicle in two-dimension collision accident has significant theory and practice meaning to microcosmic analysis of collision accidents and accident obligation identification.By using the method of dynamics modeling, the dynamics model and the movement trajectory model of accident vehicle in collision have been studied. By using the emulation experiments done by the PC-Crash software, the dynamics model of accident vehicle in collision has been tested. By using the iteration method, the movement trajectory model of accident vehicle has been settled. By hypothesis testing, the correction coefficients of accident vehicle's moment of inertia calculate formulas have been calibrated. Through comparison analysis, the differences between calculation results of the movement trajectory in the same accident, which are calculated by trajectory reconstruction model and PC-Crash software, have been discussed.The mechanics analysis of the whole vehicle body has been done, and the movement trajectory model of vehicle in two-dimension collision has been improved. By researching the dynamics model of vehicle in two-dimension collision, the relationship of vehicle movement state between pre-impact and post-impact has been set up. According to the typical accident cases of Heilongjiang province, the trajectories of accident vehicles have been reconstructed respectively, by using trajectory reconstruction model made by this paper and traffic accident emulation reconstruction analysis software PC-Crash. By using trajectory error evaluation indexes of accident vehicle defined by the paper, the results of trajectory reconstruction have been analyzed contrastively. The innovation of this paper consists of the following items. The definited methord of the accident impact point has been set up. The calculate formulas of vehicle's moment of inertia which is relative to vehicle's center of mass have been improved. The relationship between the vehicle's side slip angle and steer angle has been set up, and the movement trajectory model of vehicle in two-dimension collision accident has been improved. The trajectory error evaluation indexes of accident vehicles have been defined. According to the mechanics characteristic of two-dimension collision accident, two categories which are two-dimension centripetal collision and two-dimension non-centripetal collision have been classified. For two-dimension centripetal collision, the relationship model of plastic deformation and effective impact speed has been used to calculate vehicle speed before impact. For two-dimension non-centripetal collision, the classical impact dynamics model has been used to calculate vehicle speed. By using the actual accident cases, the trajectory reconstruction model of the vehicle in two-dimension collision accidents has been tested. The results indicate that the trajectory reconstruction model can describe the movement trajectory of vehicle in the course of two-dimension collision accidents exactly without considering the instances of twice or more times impacts.