Output feedback design for aircraft with ill-conditioned dynamics

Singular perturbation concepts are exploited to develop a procedure for designing a dynamic output feedback controller. It is assumed that the original system is ill-conditioned in the sense that the plant contains widely separated dynamics requiring stabilization, and that the measurements are composed of a linear combination of slow and fast variables. A two time scale design approach results which depends on two-way control spillover suppression. An application to active control of aircraft wing flutter modes is used to illustrate the design method.