Long-Term Robot Navigation in Indoor Environments Estimating Patterns in Traversability Changes

Nowadays, mobile robots are deployed in many indoor environments such as offices or hospitals. These environments are subject to changes in the traversability that often happen following patterns. In this paper, we investigate the problem of navigating in such environments over extended periods of time by capturing and exploiting these patterns to make informed decisions for navigation. Our approach uses a probabilistic graphical model to incrementally estimate a model of the traversability changes from the robot's observations and to make predictions at currently unobserved locations. In the belief space defined by the predictions, we plan paths that trade off the risk to encounter obstacles and the information gain of visiting unknown locations. We implemented our approach and tested it in different indoor environments. The experiments suggest that, in the long run, our approach leads robots to navigate along shorter paths compared to following a greedy shortest path policy.