Influence of Spatial Geometric Properties of Highway Alignments on Vehicle Kinematics

Abstract:

Firstly, curvature and torsion instead of traditional twodimensional (2D) horizontal and vertical indexes were used to describe the spatial geometric properties of highway alignment according to the curve theory of differential geometry. Then the vehicle was treated as a rigid body and a new motion model was established with the curvature and torsion as the control variables base on the Frenet Frame. Finally, an example was analyzed to demonstrate the influence of spatial geometric properties of an existing highway on vehicle kinematics. It is found that the setting of curvature plays a leading role in the spatial motion, while the torsion affects the motion less. The coupling effects of horizontal and vertical alignments were ignored during traditional design process, which led to the continuity degradation of curvature and torsion, and directly affected the smooth variation of vehicle motion and driving comfort.