Assistive navigation of a robotic wheelchair using a multihierarchical model of the environment

This paper presents ail application of a multihierarchical, symbolic model of large-scale space for representing the environment of a robotic wheelchair that has been automated for assistance to mobility impaired people. Rehabilitation robotics has an issue that is not present in mobile robotics: the need for an interface with the human driver. Our hierarchical model demonstrates its suitability to represent the environment in a structure easily manageable by the human (it serves as a good interface with the human's cognitive map) and. at the same time, provides better performance than flat topological maps in route planning. This is achieved by including multiple hierarchies of abstraction in the model, which improves the adaptation of the vehicle to its tasks and environment. The paper describes and illustrates an experiment in which the, wheelchair, with the assistance of the human driver, builds a model of space and uses it for autonomous navigation.