Hierarchical Reasoning About Direction Relations

Reasoning about direction relation is an important aspect of spatial reasoning. This paper mainly researches the representation and reasoning of direction relation based on hierarchy. We propose the hierarchical structure based on overlay of area, put forward a generalized direction GD₈ based on D₁₄ in need of reasoning. Assuming that direction relations about objects within same father node are given, an algorithm is presented for the inference of relations between objects within different father nodes.