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

Open-loop estimation methods are commonly used in mobile robot applications. Their strength lies in the speed and simplicity of an estimate. However, these methods can sometimes lead to inaccurate or unreliable positional estimates. Using one or more optical flow sensors, a method has been developed which can accurately track position in both ideal kinematic conditions and otherwise. Using optical flow techniques and available sensors, reliable positional estimates are made. Location of the sensors has also been investigated in order to minimize errors caused by inaccurate sensor readings. Finally, the method is implemented and tested using a potential filed 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 kinematic violations (such as wheel slip) occurred.