Gain-scheduled linear fractional control for active flutter suppression

A gain-scheduled controller for active Butter suppression of the NASA Langl ey Research Center's Benchmark Active Controls Technology wing section Is p resented. The wing section changes significantly as a function of Mach and dynamic pressure and is modeled as a linear system whose parameters depend in a linear fractional manner on Mach and dynamic pressure. The resulting g ain-scheduled controller also depends in a linear fractional manner on Mach and dynamic pressure. Stability of the closed-loop system over a wide rang e of Mach and dynamic pressure is demonstrated. Closed-loop stability is de monstrated via time simulations in which both Mach and dynamic pressure are allowed to vary in the presence of input disturbances. The linear fraction al gain-scheduled controller and an optimized linear controller (designed f or comparison) both achieve closed-loop stability, but the gain-scheduled c ontroller outperforms the linear controller throughout the operating region .