Edge Visibility Regions - A New Representation of the Environment of a Mobile Robot

This paper proposes a novel representation of the free space of mobile robot by distinct, non-overlapping regions called Edge Visibility Regions (EVRs). An algorithm to partition the free space into EVRs from a given stored world model is presented. The EVRs have the property of capturing the geometric relations between the features in the world model with respect to their visibility from different positions in the plane in which the robot navigates. Associated with each region is a list world model features that are visible in that region called the visibility list (VL). Also computed and stored for each edge in the VL of an EVR is a range of orientations of the robot for which this edge is visible in the region. An analytic bound on the maximum number of EVRs that will be generated for a given world model of the environment is derived. The advantages of an EVR representation in positional estimation and path-planning tasks of the mobile robot are discussed.