Visual Path Following with a Catadioptric Panoramic Camera

In this paper we describe the use of a catadioptric panoramic system, built with a spherical mirror, for navigation tasks, namely visual path following. We define Visual Path Following as a method whereby once a robot has arrived at the start of a previously specified path, it can perform path following to a given location relying on visual tracking of features (landmarks) alone. The geometry of the catadioptric sensor and the method of image unwarping to obtain a bird’s eye view of the ground plane are presented. The ground unwarp representation significantly simplifies the solution to navigational problems, since the image coordinates differ from ground coordinates by a simple scale factor, thus eliminating any perspective effects. Preliminary experiments with a mobile robot equiped with the described catadioptric panoramic sensor are detailed. Finally, encouraging and promising results obtained are presented.