With the number of large-scale facilities, malfunctioning spacecraft, and debris expected to increase in space, on-orbit servicing, including assembly, monitoring, maintenance, refueling and deorbiting, has become a major concern in space missions. Space robots can efficiently cope with a large number of on-orbit servicing missions while avoiding the high risks and reducing costs of extravehicular activity. The challenges of space robots with multiple arms include the complex dynamics and the coupling between the floating base and the end-effector. To handle these problems, a dynamics model with topological structure is firstly established for a four-arm space robot based on the kinematic chain symbolic calculus system and Axis-Invariants, which have the benefits of iterative structure and can avoid complex derivation of traditional dynamics modeling methods. Then, an attitude stabilization strategy consisting of improved nonlinear model predictive control and a hybrid actuator is implemented to handle the disturbance generated by the manipulation of multiple robot arms. The hybrid actuator can provide accurate control torque while simultaneously avoiding the singularity and saturation of the control moment gyro and reaction wheel, respectively. Finally, a scenario of space debris recycling is used to demonstrate the effectiveness of the proposed modeling and control strategy for on-orbit servicing missions with multiarmed space robots.

随着大型设施的数量，航天器故障以及空间碎片的增加，在轨维修，包括组装，监测，维护，加油和脱轨，已成为太空飞行中的主要问题。太空机器人可以有效地应对大量在轨维修任务，同时避免了高风险并降低了舱外活动的成本。多臂空间机器人面临的挑战包括复杂的动力学以及浮动基座和末端执行器之间的耦合。为了解决这些问题，首先基于运动链符号演算系统和轴不变式，为四臂空间机器人建立了具有拓扑结构的动力学模型，它们具有迭代结构的优点，并且可以避免传统动力学建模方法的复杂推导。然后，实现了由改进的非线性模型预测控制和混合执行器组成的姿态稳定策略，以处理由于操纵多个机械臂而产生的干扰。混合动力执行器可以提供精确的控制扭矩，同时避免分别产生控制力矩陀螺和反作用轮的奇异和饱和。最后，使用空间碎片回收方案来演示所提出的建模和控制策略对多臂空间机器人在轨维修任务的有效性。实施了一种由改进的非线性模型预测控制和混合执行器组成的姿态稳定策略，以处理由于操纵多个机械臂而产生的干扰。混合动力执行器可提供精确的控制扭矩，同时避免分别产生控制力矩陀螺和反作用轮的奇异和饱和。最后，使用空间碎片回收方案来演示所提出的建模和控制策略对多臂空间机器人在轨维修任务的有效性。实施了一种由改进的非线性模型预测控制和混合执行器组成的姿态稳定策略，以处理由于操纵多个机械臂而产生的干扰。混合动力执行器可以提供精确的控制扭矩，同时避免分别产生控制力矩陀螺和反作用轮的奇异和饱和。最后，使用空间碎片回收方案来演示所提出的建模和控制策略对多臂空间机器人在轨维修任务的有效性。