Environment Exploration Using ``Just-in-Time'' Sensor Fusion

Abstract

This paper describes an approach to combining range data from both a
set of sonar sensors as well as from a directional laser range finder
to efficiently take advantage of the characteristics of both types of
devices when exploring and mapping unknown worlds. We call our
approach ``just in time sensing'' because it uses the more accurate
but constrained laser range sensor only as needed, based upon a
preliminary interpretation of sonar data. In this respect, it
resembles ``just in time'' inventory control which attempts to
judiciously obtain materials for industrial manufacturing only when
and as needed. Experiments with a mobile robot equipped with sonar and
a laser rangefinder demonstrate that by judiciously using the more
accurate but more complex laser rangefinder to deal with the
well-known ambiguity which arises in sonar data, we are able to obtain
a much better map of an interior space at little additional cost (in
terms of time and computational expense).