Abstract— This paper presents a new approach to the intralocalization among a team of robots working in constrained 3D space of urban environments. As the base formation, a team of three ground robots and one wall-climbing robot are deployed on ground and on a wall or ceiling, respectively. The three ground robots localize themselves using an existing panoramic vision-based method. However, no existing method can uniquely determine the pose of the climbing robot based on the positions of three ground robots in its image and in the world coordinate systems; up to four valid solutions could exist using known algorithms, although only one is genuine. By carefully examining these methods, two new algorithms for uniquely locating the climbing robot are proposed. The first algorithm makes use of the straight line constraint of robot motion and can uniquely determine the pose of climbing robot by moving the climbing robot straightly for two small steps. The second algorithm is based on the...