Location Representation and Cardinal Direction Relation Reasoning Based on Qualitative Coordinates
Hao Zhong-xiao · Xi'an Jiaotong Daxue xuebao · 2010
Since all the existing models for position relation concentrate on position between points,the concept of qualitative Cartesian rectangular coordinate is proposed and then a model based on the concept is presented for the position relations between regions.The model uses a position matrix to represent position relations.The position matrix records intersections among the qualitative position region of the primary object and the qualitative position regions of the reference objects.The model well reflects the shapes of objects and the spatial configurations among objects,and excellently represents position relations among regions.Direction and distance are effectively integrated by means of qualitative Cartesian rectangular coordinates to form a unified model for representation and reasoning.In order to improve the precision of reasoning with cardinal direction relation,an algorithm is proposed based on the proposed model and is shown to be correct in theory.The results of both theoretical analyzing and experiments show that the algorithm indeed improves the precision of reasoning.