On Robust Control of Wing Rock using Nonlinear Control

Nonlinear control theory of uncertain systems is applied to the high angle-of-attack flight dynamic phenomenon of wing rock. Wing rock, an unsteady aerodynamic effect, is an undamped oscillation primarily in the roll axis and is exhibited by many modern combat aircraft. It causes maneuver limitations ranging in severity from degradation in tracking effectiveness to loss of control. Robust control is investigated for a generic nonlinear wind tunnel model of a modern combat aircraft that exhibits wing rock. Feedback control is derived using the nonlinear control approach of uncertain systems. A typical example is presented.