Passive stereo range imaging for semi-autonomous land navigation

Many navigation tasks, such as the use of unmanned vehicles for planetary exploration or defense reconnaissance, require onboard range sensors to automatically detect obstacles in the path of a vehicle. Passive ranging via stereo triangulation, or stereo vision, is a very attractive approach to obstacle detection because it is nonemissive, nonmechanical, nonscanning, and compatible with stereographic viewing by human operators. However, several problems have restricted the practicality of stereo ranging in the past, including limitations on the speed, reliability, and generality of existing stereo matching algorithms. This situated has changed, because the Jet Propulsion Laboratory (JPL) recently demonstrated the first semi-autonomous, robotic traverses of natural terrain to use stereo vision for obstacle detection, with all computing onboard the vehicle. This article reviews the main algorithmic paradigms for stereo vision, describes a near realtime stereo vision system developed at JPL, and presents experimental results that demonstrate the emerging practically of stereo vision for obstacle detection in semi-autonomous land navigation. © 1992 John Wiley & Sons, Inc.