随机初值条件下基于翼伞的无人机回收方法

Parafoil-based UAV Recovery System Under Random Initial Conditions

翼伞回收系统由柔性伞衣和所回收负载组成,存在对着陆场要求低、飞行安全稳定、可雀降无损着陆等独特优势,在无人机回收、物资空投等军用及航空航天领域都发挥着不可替代的重要作用。翼伞回收系统依靠柔性伞衣提供升力,但伞衣存在复杂的非线性动力学特性,导致其控制难度较传统刚性飞行器更高。针对该问题,基于部分假设,通过对柔性伞衣和系统负载间的相互作用进行动力学分析,建立翼伞回收系统的简化动力学模型。基于自抗扰控制技术设计水平控制器与归航策略,实现随机初值条件下的翼伞高精度归航,从任意初始位置及角度将无人机精确地运输至目标位置。飞行测试结果表明:所建立的动力学模型可为翼伞的实际飞行实验提供仿真调试环境,实现控制器参数调节;在15次翼伞归航控制实验中,翼伞系统的平均归航落点误差为21.9 m。

A parafoil recovery system consists of a flexible parafoil wing and a payload.It has unique advantages such as low requirements for landing ground,flight stability,and flared landing.As a result,this system is indispensable for airdrop supplies and recovery of unmanned aerial vehicles(UAVs).Considering that the parafoil system relies on a flexible wing for lift,it exhibits complicated dynamic characteristics.Tracking the trajectory of such a flexible aircraft is much more challenging than tracking a traditional rigid one.For solving this problem,this study first analyzes the forces between the flexible wing and the payload,and builds an accurate dynamic model of the parafoil recovery system.Then,based on the active disturbance rejection control theory,the horizontal controller and homing strategy are designed to realize the homing control under random initial condition.The UAV will be transported to the target position from a random initial yaw angle.Lastly,the results of the flight tests indicate that the simplified model can provide the simulation environment for the actual flight test,and realize the adjustment of the controller parameters.The average landing error of the parafoil system is 21.9 m in fifteen homing control tests.