The Estimation Of Vehicle's Collision Angle Based On The 3D Reconstruction Technology

Traffic managers should measure the responsibilities of the accident after traffic accident happening.However,the correct measurement requires the clear cognition of the traffic accident's form for the traffic managers.Traffic managers and traffic accident researchers should make a reasonable and accurate judgment of the accident participants' movements before and after the accidents.So the analysis of the traffic accident's form is of great importance and the analysis of collision angle plays a significant role in the traffic accident's form.It's difficult for the investigators to analysis the vehicle's crash angle without surveillance video.In order to solve the problem,an estimating method of vehicle's collision angle based on 3-D Reconstruction has been proposed in the thesis.Firstly,the vehicle's crash angles have been analyzed based on the 3-D reconstruction.The exist defects of the 3-D reconstruction applying for the investigation of the traffic accident are analyzed.And then an optimized 3-D reconstruction method is proposed.That the noises' handling and simplifying of the 3-D points which could rise the computing efficiency with keeping the original points' features has been studied.The montage algorithm of the multi-points-clouds which could make a completer reconstruction has also been studied.3D Hough method is used to recognize the stitching balls and these balls are used to montage the multi-points-clouds based on ICP algorithm.The render of the 3-D data based on the data provided by 3-D laser scanner has been done which could make a realer display.In a word,a 3D Reconstruction method that is suitable for the traffic accident scene has been proposed in the thesis,which enriches the method of 3D Reconstruction.Secondly,a math model of the collision angles has been proposed to analysis the relationship of the collision angle and the collision distortion.The math model involves the distortions and the normal vectors of the collision region.The normal vectors have been calculated based on the Delaunay algorithm.As for the directly Delaunay triangulation of the large points in space is of lower efficiency,disorganization and topological incompatibility,the reflection-based Delaunay triangulation algorithm has been innovated in the thesis.The comparison of the directly Delaunay triangulation and the proposed novel reflection-based Delaunay triangulation algorithm has shown the proposed method triangulates better and it's more suitable to the thesis' s surface reconstruction for the proposed reflection-based Delaunay triangulation algorithm aims at the deformation surface in traffic accident.After triangulating the triangular meshes,the normal vectors of the points can be calculated.And after calculating the points' normal vectors and distortions,the collision experiments and the real car collision accident has proved the validity of the proposed model.The results predicate the model is of the best applicability for the front collisions,which provides an inaccuracies lower than 5°,while that the others are lower than 10°.It indicates the model is applicable on the slight single traffic accidents.At last,the software named The Estimation of Vehicle's Collision Angle Analysis System based on 3D Reconstruction which is written during the thesis' s writing is introduced in the thesis.The software could achieve the functions such as the points' input and output,points' handling,triangulating,calculating the normal vectors and analyzing the collision angel.The software provides a basic analysis tool for the investigation and identification of the traffic accidents.The results of the thesis provide a basic method for analysis the traffic accident's form,and study the 3-D reconstruction method which is applicable for traffic accidents,which provide reference resources for Chinese traffic accident investigating and identification.