An Investigation into Alternative Methods for the Defuzzification of an Interval Type-2 Fuzzy Set

The number of applications of interval type-2 fuzzy logic to real world problems is growing. To date such systems have used type-reduction or an approximation of type-reduction to arrive at a final crisp output from the system. This paper describes the novel direct defuzzifier for interval type-2 fuzzy sets. A number of fuzzy systems are compared with the direct defuzzifier. We compare each defuzzifiers output surface in a simple rule-based system. The direct defuzzifier compares favourably with the type-reduction method under the minimum t-norm. We found that the non-stationary approach provided interesting results.