空间机械臂末端工具的研制及其操作策略的研究

发布时间：2018-05-15 12:43

本文选题：在轨维护 + 末端操作工具　；参考：《哈尔滨工业大学》2017年硕士论文

【摘要】：随着空间技术的快速发展,舱外和空间任务日趋复杂多样,大量功能各异的空间飞行器被发射到太空。目前,各国的研究重点已经不仅仅是复杂航天系统的发射,而是如何保证已发射的航天器能够安全、稳定和长久地运行并完成空间任务。因此,空间在轨维护技术已成为当前的研究热点与难点。空间环境存在高真空、高辐射等复杂多样的特性,使宇航员的舱外维护活动成本高并伴有高风险性。由空间机器人代替宇航员进行在轨维护,可以有效降低成本、减小危险并能长期可靠地工作。在空间机器人技术领域,针对航天器进行拆卸、维修与组装,研制空间机械臂末端操作工具也是关键技术之一。通过对国内外现有相关项目研究成果的研究,本文研制了一系列针对常用连接件进行拆装的空间机械臂末端操作工具。首先,针对在轨维护任务和设计指标要求,提出了空间机械臂末端工具的总体设计方案。对常用螺纹连接件的特点进行了综合分析与对比,设计了3种拆装工具,并通过三维建模软件完成了所有零部件的设计、虚拟装配、干涉检查和重量预测;考虑到由关节柔性和运动误差等因素引起的机械臂末端径向位置偏差,提出了一种基于双十字滑块结构的偏差补偿方案,并对滑块的运动特性与传动效率进行了分析;设计了工具与末端执行器对接的统一接口,使工具安全、可靠地安装在执行器上,并接受其传递的两种动力,由仿真分析验证了接口的位姿容差能力;对工具的核心功能进行了分析与讨论,通过分析计算与有限元软件对结构复杂的零部件进行了强度校核。然后,研究了空间机械臂的控制策略以满足在轨维护任务中对工具进行操作的需求。结合螺钉的拆装任务讨论了机械臂在不同阶段控制模式的切换;鉴于维护任务的准备阶段对位置精度的需求,讨论了PD与计算力矩两种控制方法,并通过仿真进行了对比分析;为满足工具对接与连接件拆装阶段对机械臂柔顺性的需求,建立了基于位置的阻抗控制算法,由仿真分析验证了其控制效果。最后,研制了操作工具的实体样机,搭建了相应的实验平台,并开展了相关的实验验证。为验证操作工具的基本功能,进行了位置偏差补偿、夹持爪收放实验,并分析了实验结果;为验证工具的整体性能与相关控制策略,进行了连接件的拆装实验,实验结果表明:本文研制的操作工具设计方案可行,满足设计指标,选用的控制策略合理。
[Abstract]:With the rapid development of space technology, extravehicular and space missions are becoming more and more complex, and a large number of space vehicles with different functions have been launched into space. At present, the research focus of various countries is not only the launch of complex space system, but also how to ensure that the launched spacecraft can operate safely, stably and permanently and complete the space mission. Therefore, the space-in-orbit maintenance technology has become the current research hotspot and difficulty. The space environment has many complex characteristics, such as high vacuum, high radiation and so on, which makes the extravehicular maintenance of astronauts high cost and high risk. The space robot can effectively reduce the cost, reduce the danger and work reliably for a long time by replacing the astronauts for on-orbit maintenance. In the field of space robot technology, it is also one of the key technologies to disassemble, maintain and assemble spacecraft, and to develop the terminal operation tool of space manipulator. Based on the research results of related projects at home and abroad, a series of space manipulator terminal operation tools are developed for disassembling and assembling common connectors. Firstly, according to the requirements of on-orbit maintenance task and design index, the overall design scheme of the space manipulator end tool is proposed. The characteristics of common threaded connectors are analyzed and compared. Three kinds of disassembly tools are designed, and the design of all parts, virtual assembly, interference inspection and weight prediction are completed by 3D modeling software. Considering the radial position deviation of the end of the manipulator caused by the joint flexibility and motion error, a deviation compensation scheme based on the double-cross slider structure is proposed, and the motion characteristics and transmission efficiency of the slider are analyzed. The uniform interface between the tool and the terminal actuator is designed, which makes the tool secure and reliable installed on the actuator, and accepts the two kinds of power transmitted by it. The tolerance of the interface is verified by the simulation analysis. The core function of the tool is analyzed and discussed, and the strength of the parts with complicated structure is checked by means of analysis, calculation and finite element software. Then, the control strategy of space manipulator is studied to meet the need of tool operation in orbit maintenance mission. Considering the need of position precision in the preparation stage of maintenance task, the PD and torque control methods are discussed and compared by simulation. An impedance control algorithm based on position is set up to meet the requirements of tool docking and connection disassembly and assembly. The control effect is verified by simulation analysis. Finally, the prototype of the operation tool is developed, the corresponding experimental platform is set up, and the relevant experimental verification is carried out. In order to verify the basic function of the operation tool, the position deviation compensation, gripping claw retraction experiment, and analysis of the experimental results are carried out, and in order to verify the overall performance of the tool and the related control strategy, the disassembly and assembly experiments of the connecting parts are carried out. The experimental results show that the design scheme of the operating tool is feasible, the design index is satisfied, and the control strategy is reasonable.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP241

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