小 型 无 人 直 升 机 建 模 与 鲁 棒 飞 行 控 制

To address the modeling and robust flight control problem of small-scale unmanned helicopters，a cascade robust flight control framework combining H_∞ mixed sensitivity control and μ synthesis is proposed，considering the measurement noise，wind disturbance，and system parameter perturbation during flight. Firstly，a nonlinear dynamics model of the small-scale unmanned helicopter，including its thrust iterative solution algorithm and main rotor’s flapping dynamics，is constructed，taking into account the model authenticity and computational complexity. Secondly，the model is linearized at the hovering mode，and Notch filters are designed for the lateral and longitudinal channels to improve the open-loop underdamping characteristics，so as to reduce its control difficulty. Subsequently，in the robust flight control system，fast response of the inner-loop states is realized by the less conservative μ synthesis method，and the influence of disturbances on the outer-loop states is suppressed by H_∞ mixed sensitivity control. Finally，simulation experiments in the non-nominal case shows that the robust flight control system designed in this paper has more stable control performance compared with the PID control system，proving its effectiveness and superiority.