Map building for a mobile robot equipped with a 2D laser rangefinder

This paper describes a method of building a map of the environment for a mobile robot equipped with a radial laser scanner. This sensor radially scans in a plane parallel to the ground providing a two-dimensional description of the environment. From this information, the map builder produces a set of (typically) short line segments which approximate the shape of almost any kind of environment (local map). As the robot moves, the different local maps obtained are integrated into a global map, representing, thus, the whole environment observed by the robot during its navigation. In particular the authors focus their attention on the update process of the global map. The proposed algorithm introduces what the authors call a “viewing sector” as a simple mechanism to reduce the number of local map segments to be checked for correspondence for each particular segment from the global map. A line segment fragmentation process is also used in order to manage partial correspondence between segments from both maps. The authors present experimental results obtained with this system that demonstrate successful map building