<title>Range sensory-based robot navigation in unknown terrains</title>

Abstract

The navigation problem of autonomous mobile robots (AMRs) through unknown terrains, i.e. terrains whose models are not a priori known, is considered. The word terrain means both the ground surface and the obstacles which may appear in the environment. Obstacle detection is sufficient for navigation on a flat terrain with discrete obstacles. When the terrain is uneven a local elevation map representing the terrain irregularities is essential. An algorithm is presented to navigate the AMR using radar range sensory data, among arbitrary obstacles, on a ground surface which is not completely flat, i.e. some rough regions or discontinuities of terrain elevation, as in the case of bumps and holes, may appear. Range sensory data is transformed into representations, for both the terrain surface features and the obstacles, that can be used by the navigation decision-making components of the system. The navigation problem involves integration between obstacle avoidance and terrain acquisition. The AMR builds the terrain model as it navigates and constitutes a local-free space for subgoal selections. The AMR modeled by its bounding circle and any positional uncertainty is accounted for in the navigation algorithm. Properties of the algorithm are illustrated by simulation examples.