Robust attitude control for a tail-sitter aircraft

Many challenges of modeling and control exist in the tail-sitter aircraft, including parameter uncertainty, highly coupling, nonlinearity, and external disturbance. In this paper, the model of a tail-sitter aircraft is simplified at the nominal condition to obtain the nominal linear invariant model. Then a robust controller based on the H
_∞
control theory is proposed to deal with the attitude tracking control problem and decrease the effects of multiple uncertainties. It is proved that the closed-loop system has robust stability, and the tracking error can converge to stability. It is shown that the proposed robust controller can maintain the attitude angle adjustment accuracy and robustness to the model uncertainty and external disturbance.