Building a floor map by combining stereo vision and visual tracking of persons

It is a fundamental problem for mobile robots to detect free regions where they can move by local sensing. One of the most popular methods for detecting free regions is to observe the floor directly. In cluttered indoor environments, however, most part of the floor may be occluded by obstacles. To resolve the problem, we have developed an alternative method in which persons walking in the same room are observed, and 2D areas swept by the persons are regarded as free regions. For this purpose, we have combined two different methods: stereo vision and visual tracking of persons. Geometrical information of static obstacles, and topological information of free regions are respectively acquired by the methods. The uncertainty analysis of the methods, and experimental results are also shown.