中文摘要：

位置关系的定性描述是指用方向关系和定性距离描述目标对象相对于参照物的位置关系的方法。此处的研究重点是采用基于投影的方向关系和定性距离建立位置关系定性描述模型，推导了位置关系的描述公式，并根据该公式研究位置关系的定性推理，用MATLAB语言模拟了位置关系定性推理。研究中，以相邻定性距离的距离范围之比k=5为例，取ε≤1／k^2，则只要δi／δj≤ε，就有δi±δj≈δj。实际上，位置关系的定性推理结果与具体的k值无关。

英文摘要：

Qualitative representation of positional information integrates the qualitative direction and distance to describe the positional relation between a target object and a reference object. The qualitative representation model of positional relation was given with the projection-based method. The positional relation formulae was derived. Based on the positional relation formulae, the qualitative reasoning of positional relation was studied, and simulated in MATLAB language. The range ratio of adjacent qualitative distances was k = 5 in the paper. ε≤1/k^2. If δi/δj≤ε, then δi±δj≈δj. In practice, the qualitative reasoning results of positional relation were not relative to the value of k.