In applications such as vacuuming, cleaning and demining, a robot must cover an unknown surface. The robot accomplishes coverage of an unknown surface by visiting all reachable surfaces in the environment. The efficiency and completeness of coverage is improved by the construction of a topological map while the robot covers the surface. The topological map is a spatial representation of the environment constructed with information gathered by the robots sensors. Robot uses the constructed topological map to plan complete coverage paths. Existing methods generally use grid maps, which are susceptible to odometry error, inaccuracies in sensors and may require considerable memory and computation. Topological map is based on topological relationships between landmarks. Landmarks are represented by corners because they are naturally ocurring features of the environment. It is rather difficult to store information about what area the robot has covered. This difficulty in storing coverage information is overcome by embedding a cell decomposition within the map. Decomposition method uses the landmarks in the topological map as its cell boundaries. The cells are ideally suited to coverage by a simple zigzag path. Covering the envrionment robot detects new uncovered cells and updates the topological map. Robot moves from one cell to another until all surfaces are covered.
Duration : 0:2:42