Traversability Metrics For Urban Search and Rescue Robots On Rough Terrain

Rough terrain, such as the rubble that we would expect to find in urban disaster areas, will likely impede robot mobility. The goal of this paper is to find methods for quantifying the difficulty a robot should encounter traversing a region of rough terrain. We construct three metrics describing rough terrain robot mobility. In order to simplify the problem we assume that the rough terrain in question can be discretized in a certain manner and then we develop the metrics for this discretized version of the terrain. Two of these metrics reflect the difficulty a robot would have trying to move over the entire region of terrain, which is what we refer to as the coverability. The other metric describes the difficulty a robot would encounter attempting to move from some fixed point on the terrain to some other fixed point, which we call the crossability. We compute some coverability numbers for NIST step fields and briefly analyze the numerical data that are obtained.