Because the environment of outdoor robot is very complicated

the visual navigation should be intelligent and robust enough. In order to improve the performance of computer vision navigation

a real time road scene understanding algorithm based on uncertain knowledge is presented in this paper. In this algorithm uncertain knowledge reasoning is applied to fuse the various image information and application knowledge

which make the algorithm can recognize the road scene robustly

even with the noise such as strong shadow and water on the road. Color information is used to obtain a coarse road region at first. And then image edge information is used to provide the precise road edge

which can meet the accuracy need of the visual navigation task. And this algorithm is well designed for real time application

which ensures that the visual navigation can make decisions in time. This algorithm has been applied on a real robot which has been tested in the real road environment for half a year. The experiment results are satisfying.