Omni-Directional Vision with a Multi-part Mirror

This paper deals with an omni-directional sensor based on a camera and a mirror generated with a surface of revolution. The requirements the device must fulfill result from its use as the main perception system for the autonomous mobile robots used in F2000 RoboCup competitions. The more relevant requirements which have been pursued are 1) range sensing in a quite wide region centered around the robot, with good accuracy; 2) sensing around the robot in a given vertical sector, in order to recognize team-mates and adversaries (all robots have a colored marker above a given height); 3) range sensing in a region very close around the robot, with the highest accuracy, to locate and kick the ball. Such requirements have been fulfilled by the design of a mirror built up of three different parts. Each part is devoted to the fulfillment of one requirement. Concerning the first requirement the approach developed is based on the design of a mirror’s profile capable to optically compensate the image distortion provided by the mirror profiles commonly used in previous literature. This approach resulted to be similar to a previous work by Hicks and Bajcsy, although independently developed by the authors.