Roborealm has an interesting tutorial on using machine vision for obstacle avoidance in ground-based vehicles. The tutorial shows a series of image processing steps which can be chained together to detect the "highest" point in an image, based on the ground color. Presumably, that high…
Shown below is a video of a robot that uses the perceived vanishing point of an image to navigate through a corridor. The robot, based on an iRobot Create, uses a standard webcam and video processing to locate the vanishing point of what it sees, and navigates towards that point. Such navigation wo…