Analysis of Map Alignment Techniques in visual SLAM systems
Mónica Ballesta, Óscar Reinoso, Arturo Gil, Miguel Juliá, Luis Payá
13th IEEE International Conference on Emerging Technologies and Factory Automation  (Hamburg (Germany), 15-18 September 2008.)
 ISBN:1-4244-1506-3  - pp. 825-832


In a multi-robot system, in which each of the robots constructs its own local map, it is necessary to perform the fusion of these maps into a global one. This task is normally performed in two different steps: by aligning the maps and then merging the data. This paper focusses on the first step: Map Alignment, which consists in obtaining
the transformation between the local maps built independently. In this way, these local maps will have a common reference frame. In this paper, a collection of algorithms for solving the map alignment are analyzed under different conditions of noise in the data and intersection between local maps. This study is performed in a visual SLAM context, in which the robots construct landmark-based maps.
The landmarks consist in 3D points captured from the environment and characterized by a visual descriptor.