关节失效后太空机械臂运动性能评估与容错路径规划研究

The construction of space station is a crucial part of our country’s aerospace development strategy. The space manipulator, as an important tool to build and maintain space stations, it’s long-term and reliable on-orbit operation directly affects the smooth implementation of the space programs. Meanwhile, as a core component of manipulators, joints’ failures seriously restrict the long-term reliable operation of manipulators. To solve this problem, the research focuses on the motion performance evaluation and the fault tolerant path planning of the failed manipulator. Firstly, the joint reliability index is introduced to analyze the reliable fault-tolerant space, and both of the load capacity and operation force of the end-effector are evaluated based on the multibody system dynamic and screw theory, so as to achieve the quantitative description of manipulators’ motion performance. Secondly, aiming at no-load operation, the set of fault tolerant configuration for each trajectory point is constructed based on the diffeomorphism characteristics of topological manifold in joint space, and on the basis, an optimization search method for global fault-tolerant path planning is explored. Finally, for load operation and assembly tasks, a trajectory optimization strategy for multiple parameters’ jump inhibition is proposed based on the matrix perturbation method, and a force control method for assembly operation is presented based on force/position double-loop robust control strategy to solve the optimization control problem caused by joint failures. The research results of the program can be applied as a theoretical guidance in revealing the motion performance of space manipulators with failed joints and achieving fault tolerant control, which is of great practical value in engineering applications as well.

空间站建设是我国航天发展战略的关键环节，太空机械臂作为空间站建设与维护的重要工具，其长期可靠在轨运行直接影响着航天计划的顺利实施。关节作为机械臂核心部件，其失效问题严重制约着机械臂可靠在轨运行，为此本课题重点研究关节失效后太空机械臂运动性能评估与容错路径规划方法。首先，融入关节可靠性分析可靠容错空间，结合多体系统动力学和旋量理论，评估关节失效后太空机械臂负载能力和末端操作力，实现对关节失效后机械臂运动性能的定量描述；其次，针对空载操作任务，基于关节空间拓扑流形的微分同胚特性构建容错构型集，探索构型集内全局容错路径的优化搜索方法；最后，针对负载操作和对接装配任务，采用矩阵摄动法提出多参数突变抑制轨迹优化策略，并基于力位并环鲁棒控制策略研究装配操作力保持控制方法，解决关节失效后太空机械臂优化控制问题。研究成果对于揭示关节失效后机械臂运动性能及实现其优化控制具有重要的理论指导意义和工程应用价值。

由于太空环境严峻、空间任务繁重且关节组成复杂，机械臂长期在轨服役面临发生关节失效风险，进而严重影响太空机械臂的可靠安全运行。本项目以关节失效后太空机械臂尽可能投入后续使用为目标，开展了关节失效后太空机械臂运动性能评估与容错路径规划研究工作，取得了如下研究成果：.融入关节可靠性指标提出了太空机械臂可靠容错工作空间分析方法，有效扩大了容错任务轨迹规划域，进一步建立了太空机械臂综合容错性能评价指标，为关节失效太空机械臂末端可达性、灵巧性及负载操作能力提供了定量评价手段；在此基础上，提出了一套完备的太空机械臂全局容错路径规划及优化方法，保证了太空机械臂在发生关节失效的情况下仍然能够以最优运动性能完成任务；针对负载操作任务，建立了太空机械臂末端操作力评估模型，并提出了故障瞬间太空机械臂关节运行参数突变抑制轨迹优化策略，不仅实现了关节失效太空机械臂末端运动及操作力保持，而且成功隔离了失效瞬间控制模型突变对太空机械臂安全运行带来的影响；最后，建立了一套能够对关节失效太空机械臂容错任务进行验证的仿真平台及地面实验平台，验证了本项目所提太空机械臂容错性能评估方法及容错路径优化策略的正确性及有效性。.研究成果对于揭示关节失效后太空机械臂运动性能退化规律及实现其优化控制具有重要理论指导意义和工程应用价值。基于本项目研究成果，课题组获省部级科技进步一等奖1项；在国内外期刊及学术会议上共计发表学术论文19篇，包括SCI检索3篇和EI检索16篇（期刊论文8篇，会议论文8篇）；申请国家发明专利7项；太空机械臂容错性能评估及容错轨迹规划等相关研究成果成功应用于空间站机械臂研制，并研制软件2套；项目申请人晋升为副教授，同时培养讲师1名，博士研究生3名，硕士研究生5名，其中2位研究生分别获校级优秀博士学位论文和校级优秀硕士学位论文。