It is known that interval type-2 fuzzy logic controllers (IT2FLC) with footprint of uncertainty (FOU) in terms of membership function (MF) have been developed as an effective control method to ensure control in systems where uncertainties and nonlinear situations are high, such as quadrotor control, and have been the subject of many studies. Designing and optimising parameters of IT2FLC controllers is complex and time-consuming. To overcome this situation, an optimisation method based on NSGA-II (Non-dominated Sorting Genetic Algorithm) was applied. ITAE (Integral Time Absolute Error) was chosen as the performance criterion. IT2FLC-NSGA-PID and NSGA-PID controllers were compared and it was observed that the IT2FLC-NSGA-PID controller gave better results. As a result, the superiority of the proposed controller over the other controllers is a better overshoot ratio, a faster settling time, a lower steady state error and a robust system response against uncertainties and disturbances in nonlinear systems.
