【作者】 赵宏超；

【导师】 张景旭；

【作者基本信息】 中国科学院研究生院(长春光学精密机械与物理研究所) ， 机械制造及其自动化， 2014， 博士

【摘要】 三十米望远镜三镜系统（TMTM3S）最突出的特点是结构庞大、工况复杂、精度高且低速性能要求苛刻，大大提高了其设计和检测的难度。TMT三镜系统的结构与常见的地平式望远镜基本相同，但工作状况却差异很大，使得其设计思路及分析方法都有别与以往的设计。本文的工作主要是针对TMT三镜系统的结构特点，通过科学的计算和仿真，选取最佳设计方案，并对结构进行相应的优化，最终达到设计要求。本文首先从系统的最低谐振15Hz设计要求出发，通过合理的刚度分配，确定各结构件的设计期望，为之后的设计分析提供指导。然后，根据三镜系统转盘的功能性要求，提出两种方案，并进行了相应的仿真和分析。对于选定的TMT三镜系统整体方案，基于工况分析，设计了从三镜镜室到三镜基座间合理的力学传递路径，进而研究了多种轴承布置形式，并通过理论计算得到三镜系统促动器力学量程以及行程的设计要求。其次，关键部件的设计方法以及复杂部件的简化手段是关键的技术要点。为了衡量TMT三镜系统的结构性能，本文建立了三镜系统的整体有限元参数化模型，并对七个主要工作位置的98个工况进行了仿真，计算得到了三镜镜面形心的平移量最大可达1.28mm，镜面法线的角位移最大可达62"，系统的第一阶谐振频率可达15.1Hz。最后，通过坐标变换的方法推导了终端设备随动直角坐标在三镜坐标系下相对于基体坐标系的转换矩阵，进而采用蒙特卡罗法对随机误差进行了仿真合成，合成结果显示，现有条件下加工和装配引入的随机误差导致的Tilt轴的测角误差最大可达4.1"RMS，并从统计学的角度上对于整个多轴系统的误差特性进行了研究。基于整体—部分—整体的思想，通过模型简化，系统级刚度分配，组件选型与设计，到最终的系统精度分析，完成了对TMT三镜系统Tilt轴系原理、结构以及误差特性的分析。本文对TMT三镜系统的Tilt轴系设计及选型进行了大量的理论分析和有限元仿真，并使用数值和工程优化手段对结构进行了相应优化。分析表明，经过本文的选型与设计，得到的TMT三镜系统Tilt轴系统的设计能够满足TMT的各方面要求。同时，本文设计过程中权衡了各组件的成本与性能的关系，达到了子系统与整体系统设计的有机结合。为解决诸多具有挑战性的问题，本文做出了大量深入的理论研究。这些研究为TMT三镜系统，以及TMT整体系统的建设完成起着重要的推动作用。同时，对大型光学望远镜的设计、加工和制造提供了大量参考。更多还原

【Abstract】 The tertiary mirror system (M3S) of thirty meter telescope (TMT) is the largesttertiary mirror in the world. It is a huge structure with high precision and wonderful lowspeed performance under many working cases, which makes it a challenge. Even more,we are inexperienced with the innovative methods to do the measurement. M3S issimilar to an azimuth-altitude (az-alt) telescope. But its working conditions are quiteeven worse, which prompts us to apply the new method to complete a perfect product.This paper mainly focuses on the design for Tilt mechanism of M3S. Many scientificcomputing and simulations are applied to study every feasible solution. And the finaldesign seems to be good according to the analysis.Above all, a stiffness allocation has been developed to guide the designer. Then,there are two plans proposed on the basis of M3S functional requirement. One is aparallel manipulator, while the other one is a classic solution. Plenty of research andsimulations are accomplished to guarantee a correct design. According to the load path,some analyses were done to determine which bearing layout is the best choice. We alsofocus on the driver design. A linear actuator is employed to supply the support force.The stroke and mounting dimensions are determined. It also attracts many attentions tostudy the key components design. It’s particularly useful that a parameterized finitemodel is constructed to investigate the mainly deflection of M3S in all the conditions.The analysis results show that the maximum deflection can be up to1.28mm and the deflection angle is about62", while the first modal frequency is15.1Hz. Finally, MonteCarlo simulation method is applied to study the pointing presion by the various errorsfrom a statistical point of view, and there are a lot of interesting conclusions, of whichthe maximum measurement error of the tilt axis is about4.1"RMS.From allocating the stiffness and working for the preliminary design to final systemaccuracy analysis, the procedure follows a reasonable design methodology. The supportprinciple of the tilt axis system and the structure characteristics even with the errorsimulation were analyzed.The design decisions were made by lots of theoretical analysis and finite elementsimulation. All analysis showed that the final design could meet the requirements.Meanwhile, it deals well with balancing the cost and the performance for eachcomponent, which makes the subsystem in keeping with the overall system.This paper completes a plenty of work for M3S, and will promote the TMTconstruction process. Meanwhile, many experiences can be learned by this paper.更多还原