Using isolated landmarks and trajectories in robot navigation

A purely topological method is explored for navigation in a large unstructured environment that contains featureless objects, using qualitative nonmetric information such as isolated landmarks and trajectories, which are defined. Given a source and a goal, the map-maker constructs a series of verbal directions, called custom map. Based on the custom map, the navigating robot is told to look for events that are characterized by spatial properties of the environment, such as isolated landmarks or distinguishing juxtapositions of landmarks. The result is efficient and reliable navigation that does not depend on detailed numeric information