Indoor Navigation of a Wheeled Mobile Robot along Visual Routes

When navigating in an unknown environment for the first time, a natural behavior consists in memorizing some key views along the performed path, in order to use these references as checkpoints for a future navigation mission taking a similar path. This assumption is used in this paper as the basis of a navigation framework for wheeled mobile robots in indoor environments. During a human-guided teleoperated learning step, the robot performs paths which are sampled and stored as a set of ordered key images, acquired by a standard embedded camera. The set of these obtained visual paths is topologically organized and provides a visual memory of the environment. Given an image of one of the visual paths as a target, the robot navigation mission is defined as a concatenation of visual path subsets, called visual route. When running autonomously, the robot is controlled by a visual servoing law adapted to its nonholonomic constraint. Based on the regulation of successive homographies, this control guides the robot along the reference visual route without explicitly planning any trajectory. Real experiment results illustrate the validity of the presented framework.