Autonomous vision-based robotic exploration and mapping using hybrid maps and particle filters

This paper addresses the problem of exploring and mapping an unknown environment using a robot equipped with a stereo vision sensor. The main contribution of our work is a fully automatic mapping system that operates without the use of active range sensors (such as laser or sonic transducers), can operate on-line and can consistently produce accurate maps of large-scale environments. Our approach implements a Rao-Blackwellised particle filter (RBPF) to solve the simultaneous localization and mapping problem and uses efficient data structures for real-time data association, mapping, and spatial reasoning. We employ a hybrid map representation that infers 3D point landmarks from image features to achieve precise localization, coupled with occupancy grids for safe navigation. We demonstrate two exploration approaches, one based on a greedy strategy and one based on an iteratively deepening strategy. This paper describes our framework and implementation, and presents our exploration method, and experimental results illustrating the functionality of the system. (C) 2008 Elsevier B.V. All rights reserved.