IT2FSs
Interval Type-2 Fuzzy Systems (IT2FSs) are a class of fuzzy logic systems that use interval type-2 fuzzy sets to represent and manage uncertainty in reasoning. In IT2FSs, the membership function for a given input is not a single value in [0,1] as in type-1 fuzzy sets, but an interval of possible membership grades. The collection of these intervals across the input space forms the footprint of uncertainty (FOU), which accounts for imprecision in measurements, linguistic terms, or rule interpretation.
A typical IT2FS architecture includes fuzzification, a rule base, an inference engine, type-reduction, and defuzzification. Fuzzification
Type-reduction is a key step that collapses an IT2 fuzzy set into a type-1 representation or a
IT2FSs offer robustness to uncertainty and noise, making them attractive for control, decision support, and pattern
Applications span process control, robotics, financial forecasting, and diagnostic systems, where explicit uncertainty modeling improves reliability