基于主动光学的大口径反射镜硬点定位技术研究

	基于主动光学的大口径反射镜硬点定位技术研究
其他题名	Hardpoints defining technologies for large mirror based on active optics
	彭尧
学位类型	硕士
导师	张景旭
	2015-11
学位授予单位	中国科学院大学
学位专业	机械制造及其自动化
关键词	大口径望远镜反射镜定位硬点定位六杆硬点装置位移型促动器主动光学
摘要	大口径望远镜主镜、副镜等反射镜相对于其镜室的位置和方向靠硬点来保证，它是主动光学的关键组成部分，对提高望远镜系统的成像质量和安全防护性能具有重要的意义，随着望远镜朝着大口径、轻量化、高分辨率的方向发展，成像系统对反射镜位姿和面形精度的敏感度逐渐增大，反射镜的定位精度指标、负载监测及安全防护等要求对硬点定位装置提出了巨大的挑战。本文对国内外大口径反射镜硬点定位技术进行了分析和总结，对用于主动光学和被动光学中的不同类型的硬点定位装置的结构、工作原理和实际应用进行了系统和详细的介绍。针对口径为8m的高刚度硼硅酸盐轻量化反射镜，设计了一套最有应用前景的六杆硬点定位装置（六个相同的硬点联结反射镜及其镜室，组成一个六杆硬点装置）。其中，每个硬点包括五大主要组件：基座、位移型促动器（由步进电机、精密行星减速器、消隙齿轮传动副、角接触推力轴承、循环式行星滚柱丝杆、位移传感器、切向支撑导向装置、旋转编码器等组成），轴向分离装置/上端双轴柔性铰链/测力传感器/扭矩限制器组件、加长臂/平衡重安装法兰/下端双轴柔性铰链组件和平衡重。本文在深入研究六杆硬点装置的结构特点及关键技术的基础上，结合运动学及动力学分析，首先设计出六杆硬点的结构，然后对其进行了有限元分析和优化，最后对六杆硬点装置的关键技术中最重要也最密切相关两项技术指标（结构刚度及定位精度）进行了研究，根据刚度及误差分析结果，提出了一系列提高其刚度、定位精度和安全可靠性的方法，以最大限度地提高其性能，优化结果为：系统一阶固有频率为16.802 Hz，单杆轴向刚度为130.6 N/um，分辨率小于4 um，满足技术指标要求。本文的研究成果还包括：基于六杆硬点装置的高刚度、高精度和安全防护要求，设计了一种循环式笼套型行星滚柱丝杆和气压式轴向分离装置，并对六杆硬点装置中的关键件柔性铰链和扭矩限制器进行了有限元分析和结构改进，得到轴向刚度分别为1060 N/um 和2741.5 N/um，满足技术指标要求。
其他摘要	Hardpoints define the position and orientation of the mirrors relative to their mirror cells, are key elements of the active optics system and play a significant role in improving the imaging quality and safety performance of the telescopes. With the development of the telescope in the direction of large aperture, lightweighted and high resolution, the sensitivity of the imaging system is sharply increasing to the position and orientation of the mirrors and theirs surface accuracy. That is, the requirement of positioning accuracy, load monitoring and safety protection of the large mirror presents a great challenge to the hardpoint positioning system. This paper, after summarizing comprehensively the principles and structures and typical representatives of all kinds of hardpoints, concludes the develop tendency of the hardpoints and discusses in detail the key structures and technologies of the hardpoints which are arranged in a hexapod configuration in view of its superiorities in comparison with other types of hardpoints. At the same time, gives out a sets of solutions for improving the positioning accuracy, axial stiffness and safe reliability of the hexapod. In this paper, a set of the most promising of the hexapod positioning system (consisting of six same hardpoint ) which will be used in 8m level active optical system is designed. Among them, each hard point includes five major components: base, displacement type Actuator (by stepping motor, precision planetary reducer, anti-backlash gear pair, angular contact thrust bearings, circulating planetary roller screw, LVDT, tangential support assemblies, a rotary encoder, etc.), the axial breakaway mechanism / upper biaxial flexure hinge / load cell / torsion limiter assembly, plus the extension arm / counterweight mounting flange / lower biaxial flexure hinge and counterweight. On the basis of in-depth study of hexapod hardpoint system, firstly, the structure of the hard point of the six bar is designed.Then the finite element analysis and optimization are carried out.At last, the most important and most closely related two technical indexes (structural rigidity and positioning accuracy) of the key technology of the six bar hard point device are studied, so that it can improve the performance of the maximum. The research results of this paper include: Based on the requirements of fuctions stiffness and precision of the hexapod positioning system, a cage-circulating planetary roller screw, a biaxial flexure hinge and the torsion limiter is designed. In addition, a high axial stiffness of the pneumatic axial breakaway mechanism is devised which compared to the traditional mechanical Overload protection device is simpler, and can achieve better results.
语种	中文
文献类型	学位论文
条目标识符	http://ir.ciomp.ac.cn/handle/181722/49240
专题	中科院长春光机所知识产出
推荐引用方式 GB/T 7714	彭尧. 基于主动光学的大口径反射镜硬点定位技术研究[D]. 中国科学院大学,2015.

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