Autonomous landing and road following using two-dimensional visual cues

This dissertation deals with vision-based perception-action closed-loop control systems based on 2-D visual cues. These visual cues are used to calculate the relevant control signals required for autonomous landing and road following. In the landing tasks it has been shown that nine 2-D visual cues can be extracted from a single image of the runway. Seven of these cues can be used to accomplish parallel flight and glideslope tracking tasks of the landing. For the road following task, three different algorithms based on two different 2-D visual cues are developed. One of the road following algorithms can be used to generate steering and velocity commands for the vehicle. Glideslope tracking of the landing task has been implemented in real-time on a six-degree-of-freedom flight simulator. It has been shown that the relevant information computed from 2-D visual cues is robust and reliable for the landing tasks. Road following algorithms were tested successfully up to 50km/h on a US Army High Mobility and Multipurpose Wheeled Vehicle (HMMWV) equipped with a vision system and on a Denning mobile robot. The algorithms have also been tested successfully using PC-based software simulation programs.