Integrating cardinal direction relations and other orientation relations in Qualitative Spatial Reasoning

摘要

We propose a calculus integrating two calculi well-known in QualitativeSpatial Reasoning (QSR): Frank's projection-based cardinal direction calculus,and a coarser version of Freksa's relative orientation calculus. An originalconstraint propagation procedure is presented, which implements the interactionbetween the two integrated calculi. The importance of taking into account theinteraction is shown with a real example providing an inconsistent knowledgebase, whose inconsistency (a) cannot be detected by reasoning separately abouteach of the two components of the knowledge, just because, taken separately,each is consistent, but (b) is detected by the proposed algorithm, thanks tothe interaction knowledge propagated from each of the two compnents to theother.