大型空间机械臂地面低应力装配和多维零重力试验的机理及关键技术

Large-scale space manipulator is one of the key equipment to complete missions such as construction and maintenance of space station. Precise assemble and experimental verification are key to long-term operation under the extreme space environment. However, significant differences between the environments of the space and the earth lead to that the experimental performance can hardly reflect the operational performance. Then, exploration of the differences and their formation mechanism is the inevitable course to guide the ground assembly and experiment of the space manipulator. Our country is quite lack of theory and engineering practice experience of the ground low-stress assembly, zero-gravity experiment, and reliability evaluation of the on-orbit operation, as it is the first time for us to construct the large-scale space manipulator. Focusing on the above problems, mechanism analysis, modeling and simulation, and experimental verification will be performed to study the fundamental problem of assembly error and stress, the influence and compensation of the gravity, quantitative control of low-stress assembly technology, and reliability forecast of on-orbit operation. Key scientific problems, such as characterization and transitivity of the multi-dimensional geometry error, formation and transitivity of nonlinear stress field of weak rigidity structure, compensation of gravity for multi-degree-of-freedom movement, and reliability forecast of on-orbit operation, will be handled. Systematic theory and method of the low-stress assembly and zero-gravity experiment for large-scale space manipulator will be proposed to enhance its on-orbit performance and reliability. Meanwhile, this research will provide foundation support for enhancement of operation performance and assembly of other future large-scale space mechanisms.

大型空间机械臂是完成空间站建造与在轨维护等任务的核心装备，地面精密装调和试验考核是保证其长期在空间极端环境下可靠服役的关键。但是，地面与空间环境间的显著差别导致地面试验性能难以反映在轨服役性能，探索两者的不一致性及其形成机理成为指导地面的装配和试验的必由之路。我国首次研制大型空间机械臂，在地面低应力装配、零重力试验和在轨服役可靠性评估等方面缺乏系统理论和工程实践经验。为此，本课题拟通过机理分析、建模仿真和实验验证，开展其装配误差与应力基础问题、重力影响及补偿机理、低应力装配工艺定量控制与在轨服役可靠性预测等方面的研究，解决多维几何误差的空间表征与传递、弱刚度结构非线性应力场形成与演变机理、多维运动重力补偿、在轨运行可靠性预测等关键科学问题，形成大型空间机械臂的低应力装配和零重力试验的系统理论和方法，提升其在轨服役性能和可靠性，同时，为未来其它大型空间机构装配和服役性能提升研究提供支撑。

大型空间机械臂是完成空间站建造与在轨维护等任务的核心装备，地面精密装调和试验考核是保证其长期在空间极端环境下可靠服役的关键。但是，地面与空间环境间的显著差别导致地面试验性能难以反映在轨服役性能，探索两者的不一致性及其形成机理成为指导地面的装配和试验的必由之路。我国首次研制大型空间机械臂，在地面低应力装配、零重力试验和在轨服役可靠性评估等方面缺乏系统理论和工程实践经验。.针对上述问题，本课题开展的工作内容和取得的理论成果如下：.（1）开展了影响大型空间机械臂装配误差的误差源分析，建立了各类误差源的计算方法，为机械臂装配误差传递机理研究奠定基础；.（2）构建了机械臂装配误差传递计算的数学模型，给出了机械臂关节部位复杂齿轮传动系统的传动误差，为机械臂运行可靠性分析奠定基础；.（3）优化了大型空间机械臂低应力特性装配工艺，建立了机械臂误差传递模型，提出了误差和应力耦合的机械臂低应力装配工艺优化方法；.（4）提出了重力补偿准则和指标分解方法，建立了补偿力系解析模型并给出了优化求解方法；.（5）研制了机械臂正样产品零重力装配与综合试验的零重力模拟装置，完成了机械臂初样产品和正样产品的装配及大量试验；.（6）建立了运动可靠性模型和连续轨迹可靠性模型，开展了典型工况下机械臂轨迹点位姿可靠性分析与试验。.取得的研究成果如下：.获得国家技术发明二等奖1项，国防技术发明一等奖1项；共发表相关论文24篇（SCI检索19篇），授权相关发明专利10项，受理相关发明专利20项。.研制的空间机械臂整臂装调零重力试验与验证系统首次应用于我国空间站机械臂正样产品的地面装调和试验，保证了装配精度和装配及试验状态于在轨服役状态的一致性，为大型七自由度机械臂的零重力试验的精度定量评估提供了理论依据，保证了试验的可信度，为空间站机械臂的在轨任务的顺利开展提供重要支撑。