US Patent 9632504 Robotic navigation based on building surface contours

An example method includes determining a depth map of at least one static surface of a building, where the depth map includes a plurality of surface contours. The method further includes receiving sensor data from one or more sensors on a robotic device that is located in the building. The method also includes determining a plurality of respective distances between the robotic device and a plurality of respective detected points on the at least one static surface of the building. The method additionally includes identifying at least one surface contour that includes the plurality of respective detected points. The method further includes determining a position of the robotic device in the building that aligns the at least one identified surface contour with at least one corresponding surface contour in the depth map.