Point pattern matching based visual global localization using ceiling lights

This paper proposes a new system for point pattern matching based visual global localization using spot lightings in ceiling. The proposed algorithm is suitable for system that demands high localization accuracy and fast update rate such as a service guide robot in the exhibition or fair. A single camera looking upward direction is mounted on the head of the mobile robot, and spot lighting positions are detected by thresholding and identification process. For detecting more spot lightings, we choose wide FOV lens, and inevitably there is serious image distortion. But by applying correction calculation only for the positions of spot lightings not whole image pixels, we can decrease the processing time. And then using point pattern matching and least square estimation, finally we can get the precise position and orientation of the mobile robot. Experimental results demonstrate the accuracy and update rate of the proposed algorithm in real environments.