A mobile robot using a panoramic view

Mobile robots use actually a combination of internal and external sensors to determine their position and orientation in a path following period. Incremental encoders, gyrometers are generally used to give an approximative estimation of localization. Nevertheless, the cumulative drifts of these internal sensors must be periodically corrected with an exteroceptive sensor. So, the authors present, in this paper, an optical omnidirectional sensor which can give, with an adapted software, an absolute localization. This sensor is made of a CCD video camera associated with a conic shaped reflector; so, a view of a 2 π radian field is available to compute the position of the robot. The authors report the matching algorithm allowing a local observed scene to be replaced in the global navigation area. The authors conduct the accuracy analysis of this global positioning system, and present the experimental results