With the aim of automatically reasoning with spatial aspects in a cognitive way, several qualitative models have been developed in recent years. However, there is no model to reason with several spatial aspects in a uniform way. Moreover, most of these models simplify spatial objects to points. In this paper we present the use of constraint logic programming instantiated to finite domains extended with constraint handling rules as a tool for successfully integrating the qualitative concepts of orientation, distance, and cardinal directions, using points as well as extended objects as a primitive of reasoning. The resulting model has been applied to build a demonstrator: a qualitative navigation simulator on the structured environment of our city. ©2000 John Wiley & Sons, Inc.

Humans reason about different aspects of space (such as relative orientation, cardinal directions, distance, size and shape of objects) quite easily. With the aim of simulating human behavior, several models for these spatial concepts have been developed. Cognitive considerations have made these frameworks qualitative because it seems to deal better with the imprecision that human perception provides. Unfortunately no operational model which allows to reason with all these spatial aspects in an integrated way has been developed up to now. The first aim of our research has been the integration of different spatial concepts which is accomplished by the definition of an operational model based on first order predicate logic. Constraint logic programming extended with constraint handling rules provides the level of abstraction suited for the integration of qualitative relative orientation and qualitative distance. The second aim of our work is to apply qualitative spatial reasoning to robot path planning.