公路三维动态视距研究

在分析国内外公路视距研究现状的基础上,本论文提出了公路三维动态视距及其计算思路,详细阐述了公路三维动态视距的定义、基本原理、关键技术、基本特征以及计算模型中必需的假设及约定。由于三次B样条曲线具有2阶连续性、局部性、灵活性等特征,本论文利用三次B样条曲线表征公路线形,为计算三维动态视距奠定基础的同时也为由GPS数据反算公路几何要素提供了方法。三维动态视距是在三维空间中利用空间几何向量关系进行视距计算,在计算中考虑了平纵线形、驾驶员动态视野和夜晚时车前灯照射范围的制约等因素,为更客观地评价线形连续性提供了新的思路和方法。

Research on Highway Three-dimensional Dynamic Sight Distance

On the basis of the analyses of research findings from both domestic and abroad,Highway 3D Dynamic Sight Distance (H3DSD) and the calculation methods are put forward.The definition,basic principle,key technology,basic characteristics and the necessary assumptions of the H3DSD calculation model are expounded in detail.With the second-order continuity,local,feasibility characteristics,etc.,cubic B-spline curve,as the prerequisite of H3DSD calculation,is used to represent highway alignment.The method of calculating highway geometry elements from GPS data is also provided.Using the relation of space geometry and vector,the calculation of H3DSD is done in 3D space.During the calculation,the drivers' dynamic visual angle,the limitation of the vehicle' s headlights at nighttime,and the combination of horizontal and vertical alignment,etc.are take into account.It provides a new thought and method to evaluate the consistence of highway alignment much more objectively and scientifically.