非匹配包线下无人机空基回收拖曳系统协调运动规划

Coordinating motion planning for towed cable system in UAV aerial recovery with unmatched envelope

针对非匹配包线下固定翼无人机(UAV)拖曳式空基回收过程中的浮标轨迹稳定问题,提出一种盘旋拖曳系统运动规划方法,通过实时协调母机运动和缆绳收放从而实现浮标拖曳轨道精准稳定。首先,构建气流扰动下考虑缆绳弹性和收放特性的母机-缆绳-浮标组合体多体动力学模型。继而,综合考虑拖曳系统动力学约束和母机飞行能力、缆绳收放能力等物理约束,分别建立基于母机运动和基于母机运动-缆绳收放协调的盘旋拖曳系统运动规划最优控制模型。随后,采用hp自适应Radau伪谱法将所建最优控制模型转化为非线性规划问题,并通过SNOPT求解器解算。最终,通过平静大气下母机运动规划、常值风扰下母机运动规划和常值风扰下母机运动-缆绳收放协调运动规划等典型场景下的仿真实验对比分析表明,本方法可实现一定气流扰动和拖曳系统物理约束下浮标拖曳轨道精准稳定。

This paper proposes a motion planning method that coordinates mothership movement and cable winch control to stabilize the drogue of the towed cable system during fixed-wing Unmanned Aerial Vehicle(UAV)aerial re⁃covery with unmatched envelope.A multi-link cable-drogue and mothership dynamics model under the airflow distur⁃bances was first established.Two optimal drogue trajectory control problems subject to the physical limits of the moth⁃ership and cable were then formulated,considering dynamic constraints of the towed cable and mothership.Next,the hp adaptive Radau pseudospectral method was employed to convert the optimal trajectory control problems into nonlin⁃ear programming problems which were then solved by the nonlinear programming solver software SNOPT.Finally,three typical scenarios including mothership motion planning under a quiet atmosphere and constant wind,and coordi⁃nating motion planning of mothership movement and cable winch under constant wind were conducted to verify the ef⁃fectiveness of the proposed method.Numerical results show that the proposed method can well control the drogue tra⁃jectory subject to physical limits and wind disturbances.