Experiments in free-space triangulation using cooperative localization

This paper presents a first detailed case study of collaborative exploration of a substantial environment. We use a pair of cooperating robots to test multi-robot environment mapping algorithms based on triangulation of free space. The robots observe one another using a robot tracking sensor based on laser range sensing (LIDAR). The environment mapping itself is accomplished using sonar sensing. The results of this mapping are compared to those obtained using scanning laser range sensing and the scan matching algorithm. We show that with appropriate outlier rejection policies, the sonar-based map obtained using collaborative localization can be as good or, in fact, better than that obtained using what is typically considered to be a superior sensing technology.