| Analytical design techniques for active and passive control of aero-elastic systems are presented. These techniques are based on a rational approximation of the unsteady aerodynamic loads in the entire Laplace domain, which yields matrix equations of motion with constant coefficients.; Some existing rational approximation schemes are reviewed, the matrix Pade approximant is modified, and a new technique which yields a minimal number of augmented states for a desired accuracy is presented.; The state-space aeroelastic model is used to design an active control system for simultaneous flutter suppression and gust alleviation. The design target is for a continuous controller which transfers some measurements taken on the vehicle to a control command applied to a control surface. The control parameters are constant and they are optimized to minimize any desired combination of gust response parameters in a way that assures stability over the range of varying aerodynamic parameters in the entire flight envelope.; Structural modifications are formulated in a way which enables the treatment of passive flutter-suppression means with the same procedures by which active systems are designed. |
