Navigation in hybrid metric-topological maps

We present an approach for navigation in hybrid maps consisting of a topological graph overlaid with local occupancy grids. The topological graph is built on top of a graph SLAM system, which can be efficiently optimized even for very large environments. The novel feature of our system is that it navigates locally using local metric maps, while the overall plan is formed on the topological graph. Unlike many current SLAM methods, we never reconstruct a full occupancy grid of the environment for localization or path planning. We show that our method generates near-optimal plans, and deals gracefully with changes to the map.