Mobile robot localization by remote viewing of a colored cylinder

To visually determine the position and orientation of a mobile robot from a fixed location in its vicinity, the authors have employed a cylindrical target which has different colors in each of its four quadrants. By judicious selection of the colors, segmentation of imagery from the fixed location can determine the size and centroid of the cylinder, as well as the visible color quadrants. Both the cylinder size in monocular images, and the centroid disparity in stereo pairs, are shown to provide a measure of distance. The angle of the cylinder is determined by analyzing which color quadrants are visible and to what degree. Implementation and experimental testing of this technique shows that it provides accurate localization data to within one or two pixels of error