汽车智能辅助操作系统是智能交通系统的重要组成部分，也是目前国际上的热点问题．基于计算机视觉技术的车道保持，即视觉导航是辅助操作系统的核心问题之一．该文提出一种基于单目视觉的公路分道线二维重建算法和距离测量算法．其基本思想是根据分道线灰度与几何特征建立约束方程，进而跟踪提取分道线，并用二维模型重建，在此基础上，首先获得车道保持的必要道路参数，然后在二维重建的基础上，进一步实现了基于分道线几何约束的单目测距算法．在四川省与重庆市的高速公路上的实验证明，车道保持算法的实时性与精确性已基本满足实用要求；单目测距算法的精确度也能满足安全行车防止碰撞的需要．

Vehicle intelligent auxiliary drive system is the important part of the intelligent transport system. Using computer vision technique to solve this problem is a challenge work for every researcher in this field. The lane keeping and distance measurement based on the computer vision technique is the key problems of the auxiliary drive system. This paper describes the 2D reconstruction and distance measurement algorithms based on the monocular vision. The image is captured by CCD camera on the highway. The key thought is that establishes restriction functions for lane lines, tracks and reconstructs the lane line, gets the necessary parameters for lane keeping. Then based on the 2D reconstruction and geometric restriction, the distance between the vehicle and the obstacle can be measured with a single view. This paper also analyzes the parameters of the lane and gives the rule for lane keeping for automation navigation. All the algorithms are finished by VC++6.0. The experiments on highway in Sichuan province and Chongqing city show that the lane keeping algorithm is real-time and accurate enough to utility; and the accurate of monocular measurement algorithm can be accepted by the collision avoidance. The whole system can work well with 80km/h on the highway. To improve the real-time quality of monocular measurement algorithm is the next work.