基于激光点云的事故车辆曲面重建方法

Reconstruction method of the curved surface of traffic accident vehicle based on laser point cloud

交通事故分析再现离不开事故车辆曲面模型,变形的车身成了重建的障碍。利用三维激光扫描技术这一新方法快速、高效地获取事故现场激光点云并进行预处理;针对正面碰撞后车身前部保留1/3以上未变形区域的事故车辆,综合车身尺寸、车轮型号等提取用于绘制变形曲面特征点的尺寸基准,根据变形程度划分三个重建区域,按照特征点、特征曲线、曲面的顺序,从未变形区域开始,经由过渡区域至变形区域逐步重建车身前部曲面模型。通过实例重建模型与原车身的偏差分析显示,正偏差均值1.36 cm,负偏差均值-1.14 cm,都较小,同时曲面各处正或负偏差集中于偏差值较小的区间内。表明按本文方法直接利用变形车辆就可重建出具有足够精度的车身曲面模型。该模型经进一步处理后,可用于搭建多刚体—有限元耦合车辆模型。

Curve surface model of vehicle is necessary for analysis and reconstruction of traffic acci-dent, the deformed vehicle body is the obstacle. 3D terrestrial laser scanning technology is a new means for collecting laser point cloud in the traffic accident scene quickly and efficiently. On the so-lo collision manner and above 1/3 undeformed area that collision parts remain, extracting size refer-ences for drawing feature points with vehicle body size, wheel type and so on, it is divided into three reconstructing areas according to the degree of deformation, then surface model of vehicle frontal body is gradually reconstructed from undeformed areas, transition areas to total deformed areas fol-lowing the sequence of feature points, feature curves and surfaces in every area. Taking the real frontal collision vehicle as an example to demonstrate the method, and through comparing with origi-nal automobile body, it is analyzed that both average positive and negative values are 1. 36 cm and-1. 14 cm respectively, as well as the distribution of positive and negative deviation are separately concentrated in the small value’s region. Analysis above indicates that the proposed method could be used for reconstructing the surface model which has enough accuracy with the deformed body. It could be processed for further constructing MBS-FE model.