Navigation system based on ceiling landmark recognition for autonomous mobile robot-landmark detection based on fuzzy template matching (FTM)

We propose a vision based navigation system for autonomous mobile robots that recognizes outlets of air conditioning system (anemo) located on the ceiling as landmarks. Because landmarks on the ceiling are not obstructed by other objects, robots can find them easier than landmarks on the floor. To detect the landmark, we applied the fuzzy template matching (FTM) method. Based on FTM, a fuzzy template (FT) is modeled based on the edge information of landmarks in the image. In addition, we use neural network (NN) to detect landmarks quickly. Inputs of NN are the grades of fuzzy memberships and the learned NN directs FT to the landmark in the image. Because FTM does not use image processing, except edge extraction, it does not make processing error and the landmark can be detected precisely. The navigation system can calculate the distance and the angle of the anemo from the map information. As a result, the navigation system can identify the present robot´s position and orientation. By the proposed algorithm, precise and fast landmark detection become possible even if the landmark follows the shadow