穿越微下冲气流的飞翼布局无人机控制方法

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。

A control method of flying wing UAV for penetration of microburst

Microburst is the most dangerous low-level wind shear. The control lawof flying wing UAV requires rapid response and good robustness for penetration of microburst during taking off and landing. Based on the low pitch control effectiveness at low airspeed and the high elevator additional lift of high aspect ratio flying wing UAV, a complex control scheme which integrates elevator additional lift control with aerodynamic control is proposed. Nonlinear command distribution strategy based on output error for reference is developed, and command distribution strategy based on angle of attack protection is designed. The wind disturbance and the model uncertaintiesare taken as uncertain factors. Nonlinear control law of flying wing UAV based on active disturbance rejection control (ADRC) theory is designed for estimating and compensating the wind disturbance and the model uncertainties. The simulated results show that the control method combines complex control with ADRC, makes flight path unit step response rapidly, and shortens its rise time by 64%, estimates and compensates the wind disturbance, maintains altitude loss under 2 m, protects angle of attack and keeps it under 5.5 °. Therefore, this control method provides a reference way for and finally keeping flying wing UAV safe during penetration of microburst.