The Autonomous City Explorer: Towards Semantic Navigation in Urban Environments

The Autonomous City Explorer (ACE) project aims to create a robot capable of navigating unknown ur- ban environments without the use of GPS data or prior map knowledge. The robot finds its way by interacting with pedestrians and building a topological representation of its surroundings. This paper outlines the necessary ingredients for successful low-level navigation on sidewalks, information retrieval from pedestrians as well as the construction of a semantic representation of an urban environment. A system architecture for outdoor localization, traversability assessment , path planning, behavior selection and topological abstraction in urban environments is presented. The efficiency of the proposed approach is verified by a number of outdoor experiments with the ACE robot.