Robust vibration control of a DC9 aircraft frame

An active vibration controller for a DC9 fuselage frame is proposed. The controller is based on singular perturbation theory in order to guarantee robustness properties with respect to model uncertainties and disturbances. More specifically, the control defines a time-varying sliding manifold which is designed in order to "eliminate" the modes close to disturbance frequencies, without modifying the remaining dynamics. Moreover, the proposed approach allows one to avoid discontinuities in the control signal and to bound its rate of variation to reduce the excitation of high-frequency dynamics (spillover phenomenon).