A Direction Relation Description Model Based on IT2 FLS

These existing direction models are difficult to consider the fuzziness of direction concept,the level of direction relationship,the uncertainty of spatial data,the local character and global character of spatial direction relation.Characters of direction relation and extended 8-direction asymmetry fuzzy model were introduced at first,the extended 8-direction asymmetry fuzzy model was developed after considering the location error of reference point based on interval type-2 fuzzy set,and the primary membership function and uncertainty of membership was discussed,the FOU of fuzzy directions was analyzed too.Under this model,the reasoning method was built based on IT2 FLS,the KM defuzzifier method was used in the process,and two variables were used to measure the uncertainty of direction center.This method takes the location error of reference point,cognitive habit and percentage of target in each direction tile into account.