ELK-1107-10_manuscript_1

  Type-1 fuzzy sets theory was proposed to handle uncertainty in control systems. But some cases showed some liabilities of Type-1 fuzzy sets when facing with unpredictable disturbance and uncertainties. Therefore Type-2 fuzzy sets was introduced and extended while providing more degrees of freedom in designing criteria. The most important specification of Type-2 fuzzy sets is the interval between a superior membership function and an inferior membership function which is called footprint of uncertainty. This paper presents a Bacterial Foraging Optimization approach for optimizing the parametrized membership function. The above criterion is applied to an Automatic Voltage Regulator system and results are presented and compared with previous method.