Exploration: Do we need a map?

Abstract

Exploration is one of the fundamental problems in mobile robotics. Efforts to address this problem made over the past two decades divide into two approaches: reactive approaches, that make only instantaneous decisions, and map-based approaches involving e.g. grid, metric, or topological representations. Comparative studies have so far largely focused on comparing different map-based algorithms, while no common framework to compare them to purely reactive approaches currently exists. This paper aims at creating a framework to simulate, evaluate, and compare exploratory algorithms as different as reactive and map-based approaches. Preliminary results are demonstrated for two reactive algorithms, random walk and wall follower, and one map based approach, pheromone potential field, have been implemented. Measurements of navigation success, time to success, as well as computational and memory usage reveal a dominance of simple wall-following over the map-based potential field approach, and a distinct load/efficacy trade off for random walks. These preliminary results challenge the common assumptions that maps are needed for successful and efficient exploration and navigation.