Disturbance prediction and its application to H∞ flight control

An output-feedback H_infin preview controller is proposed. The controller predicts disturbance responses by considering the disturbance derivatives and generates the optimal control input that minimizes the H_infin norm of the closed-loop transfer function. By assuming a disturbance response without a future control input, a design problem is formulated as a standard H_infin problem. The disturbance information that the controller requires is obtained by a disturbance observer. The proposed controller is combined with the disturbance observer and applied to the flight control of the lifting-body airplane dynamics. Simulation results show the effectiveness of the proposed system.