Nonlinear control design of an airfoil with active flutter suppression in the presence of disturbance

The nonlinear flutter suppression of a typical wing section is investigated. A structural nonlinearity is considered in the pitch direction. Integral-input-to-state stability (iISS) concept is utilised for the construction of a feedback controller. One of the advantages of this design is its simplicity and straightforwardness. A backstepping method is used to compare the results for the typical section, which is a multi-input system. The iISS controller has an outstanding performance in comparison to the backstepping method, especially with regards to the disturbance attenuation problem. A Lyapunov-based controller was also introduced for the system.