Yakali, Huseyin Hakan.

This thesis outlines the design philosophy and implementation aspects of a new interactive CAD tool implemented in BASIC language on an IBM PC/AT computer for single input single output (SISO) digital control systems. The direct Digital Control design method presented is classical in nature. The program main features are: (1) The use of Modified z-transform to model the effects of transport delay due to control computation time. (2) The use of windows on a split screen to allow the designer observation of the closed-loop step response while systematically shaping a root locus or synthesizing closed-loop pole/zero patterns. (3) Display of system response in between sampling instants.

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.