随着我国航天技术的发展以及对太空探索的深入，空间机械臂作为航天领域的重要设备，近年来受到了学者们的广泛关注。空间机械臂在轨工作时容错率低，难以进行维护，使得空间机械臂必须具有很高的安全性和可靠性。但是太空中的零微重力环境与地球的重力环境完全不同，如何保证机械臂在地面实验与太空环境中的等效性，成为机械臂在轨工作安全和评估其性能的关键因素。本文以天和一号空间机械臂及其地面零重力实验系统为研究对象，设计并建立了与空间机械臂等效的模拟机械臂，分别对模拟机械臂和空间机械臂在地面零重力模拟系统中，以及空间机械臂在太空自由漂浮状态下的运动学及动力学进行建模和等效性指标构建，研究了两个机械臂之间的等效关系，以及地面零重力卸载系统卸载率的等效性问题，并完成了机械臂的地面实验验证。空间机械臂及其地面零重力实验系统等效性设计与建模。根据给定的几何尺寸和重量约束条件，以保证质心位置偏差为目标，基于相似理论设计一套与空间机械臂质心和运动功能等效的模拟机械臂，为地面实验提供条件。并建立空间机械臂及其地面零重力系统的整体动力学模型，为地面零重力实验系统卸载率的指标构建奠定基础。地面零重力实验系统等效性指标构建及分析。针对机械臂实验的复杂性及连续性，提出一种基于关节扭矩的卸载率指标，该指标可以直接体现系统模拟太空环境的效果。采用该指标详细分析模拟机械臂在地面实验中的各种误差对卸载率的影响。通过模拟机械臂地面模拟实验，验证理论推导的准确性，并对该地面实验系统模拟太空零重力环境的效果进行评价。空间机械臂与模拟机械臂等效性研究。为保证模拟臂实验效果的可信度，对地面零重力模拟实验时的空间机械臂进行动力学建模和分析，分别针对机械臂臂杆的材料和构型差异进行讨论。最后完成空间机械臂地面模拟实验，验证模拟机械臂等效性研究的有效性。空间机械臂太空环境等效性研究。针对太空中自由漂浮状态下的空间机械臂系统进行了运动学及动力学分析，推导出该状态下，空间机械臂关节扭矩的表达式，进一步探讨了地面实验与太空环境的等效性问题。
In recent decades, space technology and the exploration of space of China are developed very fast. Space manipulator, which is a key of space technology, has been widely concerned by scholars in recent years. The low fault tolerance and the difficulty to maintain on-orbit require that the space manipulator should have highly security and robustness. The zero-gravity environment in space is totally different from the gravity environment on earth. How to guarantee the equivalence of the manipulator in the ground experiment and the space environment has become the key to the safety of the manipulator on-orbit. In this paper, Tianhe-1 space manipulator and its ground zero-gravity simulation system is the object of the research. The simulated manipulator equivalent to the space manipulator is designed, and the kinematics and dynamics models of two manipulators operated in simulation system are established. Furthermore, the kinematics and dynamics of the space manipulator in free-floating state in space are derivated. An equivalence index is presented to describe the equivalent relationship between this two manipulators and the efficiency of the zero-gravity simulation system. The ground tests of the manipulators are completed.Equivalence design and modeling of space manipulator and its ground zero-gravity simulation system. According to the given geometric sizes and weight constraints, and the deviation of the barycenter as the aim, a simulated manipulator which is equivalent to the barycenter and the motion performance of the space manipulator based on similarity theory. It provides the conditions for the ground experiments. The overall dynamic model of space manipulator and the zero-gravity simulation system is established, which lays the foundation for the unloading ratio index of the zero-gravity simulation system.Building and analysis of the equivalence index of the zero-gravity simulation system. Considering the complexity and continuity of the manipulator’s experiment, an unloading ratio index based on joint torques is presented. It can reflect the effect of the system simulation of space directly. In addition, this index is used to analyze the influence of various errors in the system. The experiments of the simulated manipulator operated in the simulation system were accomplished. It can verify the accuracy of the theoretical derivation and the effect of the system simulating the zero gravity environment in space.Equivalence study of the space manipulator and the simulated manipu- lator. In order to guarantee the reliability of the simulated manipulator experiment, the dynamic modeling and analysis of the space manipulator in the zero-gravity simulation system are established. The differences of the material and configuration of this two manipulator arm are discussed. Finally, the ground experiments of the space manipulator were completed to verify the effectiveness of the equivalence study of the simulation manipulator.Equivalence study of the space manipulator on space. The kinematics and dynamics of the space manipulator system in free-floating state are analyzed. The expression of the joint torques of the space manipulator are derived, and the equivalence between the ground and the space environment is discussed.
