微重力环境并联精确指向平台机构学理论与试验研究

Based on the advantages of parallel mechanisms such as bearing large, light weight, fast dynamic response and easy to realize multi-axes synchronous, this project carries out the theoretical and experimental study on precise attitude-adjusting and active vibration isolation mechanisms of large observation camera under microgravity. For the special needs of high precision attitude adjustment and vibration isolation of space station equipment, the problems such as type synthesis, kinematics and dynamics modeling, analysis of multi-dimensional stiffness and modal and dynamic coupling of frequency-division dual drive with non-holonomic constraints of parallel directing platform mechanism will be investigated. The mechanisms with double outputs (the upper-platform adjusts the attitude in large range,the lower-platform isolates vibration from medium to high frequency ) have the advantiges such as large inertia load, large workspace, high dynamic response. One dual-driven parallel precise directiing platform will be designed and manufactured innovatively based on optimization of kinematics and dynamics performance and stiffness characteristics. By direction precision test of the attitude-adjusting mechanism and multi-dimensional vibration measuremant of base mouting panel, theoretical and experimental study on real-time servo control will be carried out for parallel robot under simulated microgravity . The study will not only enrich mechanics theory, but also aim directly at the urgent need of aerospace, has great value for practical application..

本项目基于并联机构承载大、自重轻、动态响应快速、易于实现多轴联动等优点，面向空间微重力环境开展大型对地观测相机精确调姿与主动隔振系统机构学理论与试验研究。针对空间站仪器设备对高精度姿态调整与振动隔离的特殊需要，开展微重力环境下大惯量负载、高动态响应、双输出（上平台大范围调姿、下平台中高频隔振）并联指向平台机构构型综合、运动学动力学建模、多维刚度与模态分析、非完整约束下并联机构分频段双重驱动的动力学耦合等问题的研究。通过运动学、动力学性能与刚度特性优化，创新设计具有自主知识产权的双重驱动并联精确指向平台，研制样机。开展航天器相机调姿机构指向精度和安装基板多维振动检测，模拟微重力环境下并联机器人实时伺服控制理论与试验研究，为实际应用奠定基础。研究工作不仅可进一步丰富机器人机构学理论，而且直接面向我国航天急需，具有重要的理论与实际应用价值。

空间精确指向隔振平台的作用就是通过一套在线检测、实时伺服运动补偿机构系统来隔离航天器所受周期扰动的影响，为航天器所搭载的各种高精度设备提供一个稳定的工作平台，并实现精确指向。本项目基于课题组在并联机器人机构学研究方面取得的成果，进行了重载、大工作空间并联式精确指向平台机构构型创新，研究了基于微重力环境中并联多环机构运动学、动力学建模理论与耦合特征、机构刚度、主动隔振等共性科学问题，探索了空间并联式精确指向平台系统的动力特征和智能伺服控制策略。具体内容为 1).基于对航天器飞行姿态的研究，开展了并联式精确指向平台的机构构型和尺寸综合的理论研究；2).基于螺旋理论、李群/李代数和影响系数原理，研究了微重力环境非惯性坐标系下并联指向平台非完整约束动力学的建模方法，并进行了结构优化；3).考虑弹性运动副及弹性欠驱动对系统的影响，建立了在空间微重力环境的并联式精确指向平台的刚度模型和振动模型；4).研制了双重驱动形式的并联精确指向平台试验样机，并探索了非惯性系下指向平台系统的智能伺服控制策略。目前，本项目共发表学术论文20篇，其中被SCI、EI收录的论文16篇；申请发明专利20项，其中已授权9项；创新研制具有自主知识产权的 “并联式精确指向平台”。本项目在研究新型并联式精确指向平台机构学特征的基础上，发展了重载、大工作空间并联式精确指向平台机构学基础理论，丰富了并联机器人机构学理论，对设计研制能够隔离航天器多维振动且能够承受重载、具有大工作空间和高动态响应的精确指向隔振平台具有重要意义。