自由翻滚故障卫星外包络抓捕及抓捕路径优化

自由翻滚故障卫星抓捕是航天器在轨服务及空间碎片清理的基础。由于难以确定固定抓捕点及目标运动参数不确定，传统机械臂抓捕方法无法适用类似自由翻滚故障卫星的空间非合作目标。提出一种具有鲁棒性的外包络抓捕方法及抓捕路径优化方案。外包络抓捕方式能够适用于自由翻滚故障卫星抓捕问题，其特点在于，第一，由抓捕末端执行器构成的抓捕包络可以包络空间目标，约束其运动并最终实现抓捕，因此不需要固定抓捕点；第二，末端执行器构成的抓捕包络，能够约束故障卫星运动，而两者之间的摩擦可以有效消除两者之间的相对运动最终成功抓捕翻滚目标。进一步，针对外包络抓捕方法，提出了一种最小燃料消耗及最小抓捕扰动的机械臂抓捕路径。为验证外包络抓捕方法的有效性，构建旋转立方星抓捕地面实验，并利用数值仿真验证外包络抓捕机械臂最优路径规划，仿真结果验证了所提出方法的有效性。

Outside envelop grasping method and approaching trajectory optimization for tumbling malfunctional satellite capture

Capture of tumbling malfunction satellites is the basis of on-orbit servicing of spacecraft. As there is no fixed grasping point or rendezvous dock and precise motion parameters can be hardly obtained, traditional capture methods can hardly be applied in grasping of the tumbling malfunctional satellite. In this paper, a novel robust outside envelope capture approach is proposed for the tumbling malfunctional satellite. With the approach, the non-cooperative targets such as the tumbling malfunctional satellite can be captured because first, the capture envelop that is formed by the capture end-effector can constraint the motion of the malfunctional satellite, and thus there is no need for a fixed grasping point; second, the slight friction between the grasping end-effector and the malfunctional satellite can decrease the relative rotation motion between the two. Based on the envelop capture approach, the grasping trajectory for the robotic arm is optimized considering the fuel cost and disturbance to the base of the satellite. To verify the effectiveness of the grasping approach, the proposed method is applied in the tumbling cube-sat capture. The experiment and simulation results demonstrate the advantage of the proposed method.