Representing a 3-D environment with a 2 1/2 -D map structure

This paper explores the development of a two and one-half dimensional (2 1/2 -D) map structure to provide an autonomous mobile robot with a more three-dimensional (3-D) model of its environment than those afforded by current map structures. The 2 1/2 -D map structure was created by modifying the widely used evidence grid to store a height, along with a probability value, in each cell location to record the varying elevations of a 3-D environment. Results show that this map structure is capable of providing an autonomous mobile robot with a representation of a limited 3-D environment that will allow it to perform obstacle detection, path planning, and to an extent, localization.