We present the Reflectance Field Map, a reliable real-time method for detecting shiny surfaces, like glass, metal, and mirrors, with lidar. The Reflectance Field Map combines the theory developed for Light Field Mapping, common in computer graphics, with occupancy grid mapping. Like early methods for sonar-based robot mapping, we show how the addition of angular viewpoint information to a standard 2D grid map enables robust mapping in the presence of specular reflections. However unlike previous approaches, our method works in dynamic environments. Additionally, unlike recent approaches for lidar-based mapping of specular surfaces, our approach is sensor-agnostic and has no reliance on either intensity or multi-return measurements. We demonstrate the ability of the Reflectance Field Map to accurately map a campus environment containing numerous pedestrians and significant plate glass, both straight and curved. The algorithm runs in real-time (75+Hz) on a single core of a standard desktop processor. An open source implementation of the algorithm is available at https://github.com/collinej/reflectance_field_map.

We present socially-aware navigation for an intelligent robot wheelchair in an environment with many pedestrians. The robot learns social norms by observing the behaviors of human pedestrians, interpreting detected biases as social norms, and incorporating those norms into its motion planning. We compare our socially-aware motion planner with a baseline motion planner that produces safe, collision-free motion.

We present an algorithm for probabilistic topological mapping that heuristically searches a tree of map hypotheses to provide a usable topological map hypothesis online, while still guaranteeing the correct map can always be found. Our algorithm annotates each leaf of the tree with a posterior probability. When a new place is encountered, we expand hypotheses based on their posterior probability, which means only the most probable hypotheses are expanded. By focusing on the most probable hypotheses, we dramatically reduce the number of hypotheses evaluated allowing real-time operation. Additionally, our approach never prunes consistent hypotheses from the tree, which means the correct hypothesis always exists within the tree.

An autonomous vehicle intended to carry passengers must be able to generate trajectories on-line that are safe, smooth and comfortable. Here, we propose a strategy for robot navigation in a structured, dynamic indoor environment, where the robot reasons about the near future and makes a locally optimal decision at each time step.