样条函数平曲线加宽的研究

On Widening of Plane Curve of Spline Function

用改进后的样条曲线代替传统惯用的公路平面线形，具有设计合理，与行驶轨迹一致，线形柔顺，并能适应地形和车速的变化等特点，是一种更加合理的线形设计新方法．样条函数平曲线的加宽，在曲率半径最小点采用最大加宽值，两侧采用按弧长比率为参数的三次抛物线过渡变化．进一步完善了样条函数在公路平面设计中应用的理论．

Compared with traditional highway plane geometry,the improved spline curve has Charactertics Of reasonable ness,conformity with the traval tracc on curve and adaption to the loweraphry and speed variation.It is thcrefore a newmethod for geometric dcsign.when widening the plane curve of spline function,the maximum.Widening value at theminimum curvature and the cubic Parabola of are length ratio parameter at sides are adopted This method perfects the ap-plications of spline function in highway plane design.