Control of wing rock using fuzzy PD controller

Wing rock is a highly nonlinear phenomenon in which the aircraft undergoes limit-cycle roll oscillations at high angles of attack (AOA). In this paper, a simple fuzzy PD control method is employed for wing-rock suppression and tracking because fuzzy PD controller has the same performance as the conventional PD controller for linear processes, yet improves the control capability for nonlinear and uncertain processes. Simulations at various initial conditions and different AOAs demonstrate the effectiveness and robustness of the proposed scheme. Comparison with other fuzzy PD controllers in literatures is also conducted. It shows that the proposed fuzzy controller can control wing-rock with complete and fast control effect in a wide range of AOA.