Mobile robot localization by multi-sensor fusion and scene matching

This paper proposes a new localization method for indoor mobile robots. Using two cameras and one laser range finder on board a TRC mobile robot, the initial position and pose of the robot can be obtained by multisensor fusion and scene matching based on geometric hashing. No correspondence calculation and special pattern recognition are needed during the scene matching. This localization method can be implemented in five stages: (1)Model the indoor environment. Some selected indoor environment features are firstly modeled off-line into hashing tables. (2)Perform system calibration and information fusion from two cameras and the range finder. (3)Extract the vertical edge points corresponding to the horizontal scanning plane of the 2D laser range finder from the scene images and transform them into geometric invariants. (4)Perform scene matching and matching verification by geometric hashing and model back-projection method respectively. (5)Perform position and pose estimation by a least square fit method. Experimental results show that the accuracy and reliability of this localization method are quite high.