Sliding Mode Control Applied to Reconfigurable Flight Control Design.

摘要

Sliding mode control is applied to the design of flight control systems capable of operating with limited bandwidth actuators and in the presence of significant damage to the airframe and/or control effector actuators. Although inherently robust, sliding mode control algorithms have been hampered by their sensitivity to the effects of parasitic unmodeled dynamics, such as those associated with actuators and structural modes. It is known that asymptotic observers can alleviate this sensitivity while still allowing the system to exhibit significant robustness. This approach is demonstrated. The selection of the sliding manifold as well as the interpretation of the resulting linear design is accomplished in the frequency domain. The design technique is exercised on a pitch-axis controller for a simple model of the High Angle of Attack F-18 vehicle via computer simulation. A model-based tool is used for predicting task-oriented handling qualities and pilot-induced oscillation tendencies for the sliding mode controller operating with a damaged vehicle.