Application of IT2 FLS in Direction Relation Approximate Reasoning

It was necessary to consider the uncertainty of spatial data and fuzziness of relative conception in direction relation representation and reasoning, because of the fuzziness of the direction concepts and the inherent uncertainty of spatial data. The 8-direction asymmetry fuzzy model was built, in this model each primary direction tile has 60 degrees and each secondary direction tile has 30 degrees. This model was extended after considering the location error of reference point based on interval type-2 fuzzy set, and the primary membership function and uncertainty of membership value was discussed and the attribute of this model was analyzed too. Under this model, the reasoning method was built based on IT2 FLS, this method take the location error of reference point, cognitive habit and percentage of target in each direction tile into account, certain and uncertain information was considered in this method.