Obstacle Detection in Unstructured Environment with a Single Camera and Linear Method

Obstacle detection is very crucial for mobile robots. The algorithm presented in this paper makes use of motion cues in the video streams. Firstly, we calculate optical flow at feature points. Then rotation of the camera and FOE (focal of expansion) are evaluated separately. Rotation and FOE value are refined according to an iterative linear method. Finally, we get inverse TTC (time to contact) with rotation and FOE and detect the obstacles in the scene. The algorithm doesn´t need any assumption that the ground is flat or partially flat as the conventional methods. So it is suitable for outdoor unstructured environment. Experiment results show that our algorithm works well on different kinds of terrains