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微下冲气流是最危险的低空风切变形式,为在起降阶段安全穿越该气流,飞翼布局的无人机控制律应具有快速响应能力和良好的鲁棒性。针对大展弦比飞翼布局无人机舵面附加升力大和低速状态俯仰操纵效能低的特点,提出了舵面附加升力和机体气动力相结合的复合控制方案,改进了以输出误差为参考量的非线性指令分配策略,设计了基于迎角保护的指令分配策略。将风干扰和模型的不确定性视为未知扰动,采用自抗扰控制(ADRC)理论设计飞翼布局无人机非线性控制律,使之对风干扰和模型的不确定性进行估计补偿。仿真结果表明,复合控制与ADRC相结合的方法加速了航迹倾角的单位阶跃响应速度,使上升时间缩短了64%,同时能够实现对风干扰的有效观测和补偿,使高度损失低于2m;能够在风切变中有效保护迎角,使其维持在5.5°以内。因此,该方法能够为飞翼布局无人机安全平稳地穿越微下冲气流提供一种参考方案。
Micro-downflow is the most dangerous form of low-altitude wind shear, in order to safely cross the flow during the take-off and landing phase, flying wing layout of the UAV control law should be fast response and good robustness. In view of the low elevation control efficiency of large unmanned aerial vehicle (UAV) with large aspect ratio flying wing configuration and low elevation control efficiency, a composite control scheme combining additional lift of the rudder and aerodynamic force of the airframe is proposed, and the output error is taken as reference Of non-linear instruction allocation strategy, design based on angle of attack instruction allocation strategy. The wind disturbance and the uncertainty of the model are regarded as unknown disturbances. The ADRC theory is used to design the nonlinear control law of the flying wing layout UAV to estimate and compensate the wind disturbance and the uncertainty of the model. The simulation results show that the combination of composite control and ADRC accelerates the unit step response of track dip, shortens the rise time by 64%, and realizes the effective observation and compensation of wind disturbance, and the height loss is less than 2m ; To effectively protect the angle of attack in the wind shear, to maintain it within 5.5 °. Therefore, this method can provide a reference scheme for the flying wing layout UAV to penetrate the micro-downflow safely and smoothly.