On-line optical flow feedback for mobile robot localization/ navigation

On-Line Optical Flow Feedback for Mobile Robot Localization/Navigation. (May 2003) David Kristin Sorensen, B.S., Texas A&M University Chair of Advisory Committee: Dr. Sooyong Lee Open-loop position estimation methods are commonly used in mobile robot applications. Their strength lies in the speed and simplicity with which an estimated position is determined. However, these methods can lead to inaccurate or unreliable estimates. Two position estimation methods are developed in this thesis, one using a single optical sensor and a second using two optical sensors. The first method can accurately estimate position under ideal conditions and when wheel slip perpendicular to the axis of the wheel occurs. A second method can accurately estimate position even when wheel slip parallel to the axis of the wheel occurs. Location of the optical sensors is investigated in order to minimize errors caused by inaccurate sensor readings. Finally, the method is implemented and tested using a potential field based navigation scheme. Estimates of position were found to be as accurate as dead-reckoning in ideal conditions and much more accurate in cases where wheel slip occurs.