Loop closure through vanishing points in a line-based monocular SLAM

In this paper, we present a vanishing point-based two-step loop closure method in a line-based monocular simultaneous localization and mapping (SLAM) system. Vanishing points can provide absolute directional landmarks for mobile robots. This guiding ability is important in that the observation of the vanishing points is invariant with respect to the robot pose. In our system, loop closure is performed in two steps: first, the accumulated heading error is reduced using an observation of previously registered vanishing points, and second, the observation of known floor lines allows for further pose correction. In this paper, we apply this method to solve the loop closure problem for a line-based SLAM within a corridor environment where the vanishing points are usually easily detectable. Experimental results show that our method is very efficient in a structured indoor environment.