Investigation of robust model-following using a two-layered compensation scheme

A two-layered compensation scheme is developed to enhance the performance of a flight control system (FCS). The traditional explicit model-following controller designed via linear quadratic optimization is the first layer of compensation providing basic stabilization for the aircraft, while the direct adaptive controller is cascaded in the output channel or actuating path (instead of state element) to provide the overall FCS with a new level of performance. The scheme is attractive because it increases the robustness of the overall FCS and possesses a practical implementation scheme. The performance of the two-layered compensation scheme is evaluated using an F-4 aircraft model. System uncertainties arising from plant dynamics variations, disturbances, and measurement noise are used to test the performance of the two-layered compensation control law.<
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