【作者】 张大鹏；

【导师】 孙奎；

【作者基本信息】 哈尔滨工业大学 ， 机械工程， 2022， 硕士

【摘要】 随着载人航天技术的日益发展,中国空间站顺利拿到通往太空的通行证,空间站运行期间需要灵活的机械臂配合末端执行器提供在轨维护、在轨装配及性能升级等在轨服务。末端执行器作为在轨服务的关键环节,投入成本巨大,风险系数高,为了确保太空服役时捕获可靠性,地面捕获性能测试是必经阶段。为了地面模拟末端执行器空间捕获过程,检测末端执行器在工作环境中的捕获容差性能,本文基于半物理仿真的方法研制了一套末端执行器捕获容差能力地面测试系统。首先根据任务需求,进行了末端执行器捕获容差能力地面测试系统整体方案设计,介绍了系统的工作原理及组成,描述了各组成子系统的作用及其相互联系。整体系统主要包括末端执行器抓捕子系统、捕获动力学解算子系统、模拟捕获运动执行子系统及六自由度平台控制子系统。然后根据整体设计方案,采用六自由度并联平台来复现空间捕获过程中末端执行器与目标适配器间相对运动,本文选定6-UPRU作为六自由度并联平台构型,先后对其进行运动学分析、动力学分析、奇异性及工作空间分析,综合任务需求及分析结果,对六自由度并联平台进行结构细化设计工作、控制系统设计工作,搭建六自由度并联平台实物平台。接下来建立末端执行器捕获动力学模型,用以描述捕获作用力下末端执行器和目标适配器的位形关系,仿真研究捕获接触力、质量项对二者相对运动的影响,得出减小相对运动的途径;为使末端执行器捕获容差地面测试系统稳定运行,建立单自由度捕获过程系统模型,使用劳斯判据解得系统稳定性条件,绘制符合系统稳定性参数配置的伯德图,观察各参数对系统幅值裕度及相角裕度的影响,验证稳定性条件的正确性。最后规划试验流程,根据流程完成系统坐标系建立、系统通信构建、目标适配器重力补偿、电气系统设计搭建及硬件选型等试验前期准备工作。整合所有组成子系统,搭建末端执行器捕获容差能力地面测试系统,通过该测试平台模拟末端执行器捕获过程。针对目标适配器符合测试指标的各种位姿状态,进行末端执行器抓取捕获试验,测试末端执行器的捕获性能,验证本文所研制捕获容差地面测试系统切实可行。更多还原

【Abstract】 With the increasing development of manned space technology,the Chinese space station has successfully obtained the pass to space.Flexible robotic arms in conjunction with end-effector are required to provide in-orbit maintenance,in-orbit assembly and performance upgrades during space station operation.As the key link of the on-orbit service,the end effector has huge investment cost and high risk factor.In order to ensure the capture reliability during space service,the ground capture performance test is a necessary stage.In order to reproduce the end-effector space capture process on the ground and detect the capture tolerance performance of the end-effector in the working environment,a set of end-effector capture tolerance ground test system is developed based on the hybrid physical simulation method.Firstly,according to the task requirements,the overall scheme design of the ground test system for end-effector capture tolerance capability is carried out,and the working principle and composition of the system are introduced,which mainly includes end-effector capture subsystem,capture dynamics solution operator subsystem,analog capture motion execution subsystem and 6-DOF platform control subsystem,and describes the functions of each subsystem and their interrelationships.Then,according to the overall design scheme,a six-degree-of-freedom parallel platform is used to reproduce the relative motion between the end effector and the target adapter in the process of space capture.In this paper,6-UPRU is selected as the configuration of 6-DOF parallel platform.Kinematics,dynamics,singularity and working principle of 6-DOF parallel platform are analyzed successively,and structural refinement design,control system design and physical platform of 6-DOF parallel platform are carried out by synthesizing task requirements and analysis results,and build a 6-DOF parallel platform physical platform.Next,establish the end-effector capture dynamics model to describe the relative motion of the end-effector and the target adapter under the contact force,simulate and analyze the influence of the contact force and mass items on the relative motion,and obtain a way to reduce the relative motion;In order to make the end-effector capture tolerance test system run stably,a single-degree-of-freedom capture process system model is established,the system stability conditions are solved using the Rouse criterion,a Bode diagram that conforms to the system stability parameter configuration is drawn,and each parameter pair is observed.The influence of the system amplitude margin and phase angle margin verifies the correctness of the stability conditions.Finally,plan the test process,and complete the preparatory work for the test such as the establishment of the system coordinate system,the establishment of system communication,the gravity compensation of the target adapter,the design and construction of the electrical system,and the selection of hardware.Integrate all the constituent subsystems,build the end-effector capture tolerance ground test system,and simulate the end-effector capture process through the test platform.Aiming at the various pose states of the target adapter in line with the test indicators,the end-effector capture test is carried out to test the capture performance of the endeffector to verify the feasibility of the capture tolerance ground test system developed in this paper.更多还原