空间光学载荷微振动关键技术研究

发布时间：2018-12-15 19:42

【摘要】：随着空间技术的飞速发展,具有大口径、高分辨率的空间望远镜在民用、商业、军工、天文学等领域的作用越来越大。但是航天器上的运动设施(如控制力矩陀螺、反作用飞轮、太阳帆板展开机构、斯特林制冷机等)产生的微振动会极大的降低空间望远镜的成像质量。微振动形式复杂,具有幅值小、频率分布范围广、振动多向等特点,同时大型空间望远镜技术复杂,涉及学科内容多,现有的振动抑制措施和分析技术很难满足其发展需求,因此研究与之相关的微振动抑制技术、振动集成仿真分析、微振动地面模拟平台等关键技术,对于大口径空间望远镜的研制具有重要意义。设计了一种结构简单的用于空间光学载荷在轨隔振的隔振器。分析了影响隔振器三向刚度的结构参数,针对不同的载荷,探讨了隔振器的布置方式,并测试了其隔振性能。考虑到粘弹性阻尼材料的刚度和阻尼系数随温度和频率变化的特性,介绍了一种基于复刚度的分析粘弹性阻尼材料的计算方法。试验结果与分析值一致,表明文中关于隔振器的设计和分析方法有效、可靠,最后将该隔振器用于某一光学遥感器的隔振,分析结果表明该隔振器能有效抑制安装面传递给光学遥感器的微振动。开展了多维微振动隔振系统在光学载荷整体隔振中的应用研究。建立了隔振系统的理论模型,得到广义刚度矩阵和广义阻尼矩阵。推导出计算多维隔振器固有频率的数学解析式,并给出了优化隔振系统构型的优化方法。同时为评估隔振系统的隔振性能及分析微振动对光学载荷成像质量的影响,提出一种基于有限单元法的振动集成仿真分析方法,该方法在有限元中实现结构、光学、控制模型的集成,具有求解效率高、数据传递量小及计算精度高等优点。为模拟航天器上扰动源产生的微振动,提出了一种基于Gough—Stewart构型的微振动模拟平台,并开展了两代样机的研制。分别利用牛顿——欧拉方法结合拉格朗日方程和凯恩方程建立了两代模拟平台的动力学方程,并利用ADAMS和Matlab/Simulink软件进行多体系统的联合仿真,验证了理论模型的准确性。对第一代模拟平台的工作性能进行了测试。根据测试结果,利用双变量曲面拟合法对第一代模拟平台的控制算法进行了修正,大大提升了其工作性能。考虑到理论模型与实际模型之间的差异性,对微振动模拟平台的控制策略进行了研究,提出一种基于动力学模型的PI鲁棒控制。理论分析和仿真结果表明,该控制策略鲁棒性强、稳定性好,能用于模拟平台的加速度控制。
[Abstract]:With the rapid development of space technology, space telescopes with large aperture and high resolution are playing an increasingly important role in civil, commercial, military, astronomy and other fields. However, the micro-vibration generated by the motion facilities (such as the control moment gyroscope, the reaction flywheel, the solar panel unfurling mechanism, the Stirling refrigerator, etc.) will greatly reduce the imaging quality of the space telescope. The microvibration forms are complex, the amplitude is small, the frequency range is wide, the vibration is multi-directional and so on. At the same time, the technology of large space telescope is complex and involves many subjects, so the existing vibration suppression measures and analysis techniques are very difficult to meet its development needs. Therefore, it is of great significance for the development of large aperture space telescope to study some key technologies, such as micro-vibration suppression technology, vibration integrated simulation analysis, micro-vibration ground simulation platform and so on. A simple structure vibration isolator for space optical load in orbit is designed. The structural parameters affecting the three-dimensional stiffness of the isolator are analyzed. The layout of the isolator under different loads is discussed and its vibration isolation performance is tested. Considering that the stiffness and damping coefficient of viscoelastic damping materials vary with temperature and frequency, a calculation method based on complex stiffness for viscoelastic damping materials is introduced. The experimental results are in agreement with the analytical values, which show that the design and analysis method of the vibration isolator in this paper is effective and reliable. Finally, the isolator is applied to the vibration isolation of an optical remote sensor. The results show that this isolator can effectively suppress the micro vibration of the mounting surface transferred to the optical remote sensor. The application of multi-dimensional micro-vibration isolation system to the whole vibration isolation of optical load is studied. The theoretical model of the vibration isolation system is established, and the generalized stiffness matrix and the generalized damping matrix are obtained. The mathematical analytical formula for calculating the natural frequency of the multi-dimensional vibration isolator is derived, and the optimization method of the configuration of the vibration isolation system is given. In order to evaluate the vibration isolation performance of vibration isolation system and analyze the influence of micro vibration on the imaging quality of optical load, a vibration integrated simulation analysis method based on finite element method is proposed, which realizes the structure and optics in finite element method. The integration of control model has the advantages of high efficiency, low data transfer and high accuracy. In order to simulate the micro-vibration generated by the disturbance source on the spacecraft, a micro-vibration simulation platform based on Gough-Stewart configuration is proposed, and two generation prototypes are developed. Newton-Euler method combined with Lagrange equation and Kane equation are used to establish the dynamic equations of two generations of simulation platform, and the joint simulation of multi-body system using ADAMS and Matlab/Simulink software is carried out to verify the accuracy of the theoretical model. The performance of the first generation simulation platform is tested. According to the test results, the control algorithm of the first generation simulation platform is modified by using the bivariate surface fitting method, which greatly improves its performance. Considering the difference between the theoretical model and the practical model, the control strategy of the micro-vibration simulation platform is studied, and a dynamic model-based PI robust control is proposed. Theoretical analysis and simulation results show that the proposed control strategy is robust and stable, and can be used to control the acceleration of the platform.
【学位授予单位】：中国科学院研究生院(长春光学精密机械与物理研究所)
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TB535.1

【相似文献】