三次NURBS曲线在公路线形设计中的应用研究

The Research on Application of Cubic NURBS Curves in Highway Alignment Design

提出用三次ＮＵＲＢＳ曲线建立描述公路线形的统一数学模型，并对用ＮＵＲＢＳ 曲线描述公路各种线形进行了论证。该模型基于公路三维实体，应用于公路线形设计时，只需掌握公路的起讫点、交角点及曲线半径即可控制线形设计和进行局部调整。与传统设计方法和其它数学模型相比，具有高度的统一性和灵活性，为公路ＣＡＤ 软件开发提供了一条思路。

In this paper, the authors propose to build a unified mathematical model describing highway alignment using cubic NURBS curves and discuss different NURBS'expressions of a given highway alignment. This model is based on three—dimensional highway and only needs the data of starting point, finishing point, points of intersection and radius of a highway to control its alignment and adjustment. Comparing with traditional design or other mathematical model, this method has great unity and flexbility and paves a way for the soft ware development of highway CAD.