Performance analysis of the segment alignment control system for the ten-meter telescope
Performance analysis of the segment alignment control system for the ten-meter telescope
复制标题
十米望远镜分段对准控制系统性能分析
DOI：
10.1016/0005-1098(88)90090-8
复制
发表时间：
1988
期刊：
影响因子：
--
通讯作者：
W. C. Henninger
中科院分区：
文献类型：
--
作者：
J. Aubrun;K. Lorell;T. W. Havas;W. C. Henninger
凯克天文台十米望远镜（TMT）将是一个高性能的天文望远镜，能够进行前所未有的地面观测。TMT的一个独特之处在于它的主镜是由36个六边形片段组成的。将采用分段对准控制系统来实现分段主镜中玻璃整体的光学质量。像TMT这样的大型柔性望远镜的精确指向和成像问题与传统的刚性望远镜有很大的不同。这些问题的产生主要有两个原因：结构动力学效应，如对外部扰动的敏感性增强，以及节段对准控制系统与望远镜结构之间的相互作用。本研究基于TMT结构、分段对准控制系统和主反射镜上由风引起的气动载荷的数学模型，进行了结构和控制系统的综合分析。结构模型的数据来源于研究期间可用的最新设计迭代。我们利用在三个天文台所测得的实际风速，建立风荷载所产生的力的功率谱的一般模型。介绍了当前实现的控制系统中有关r.m.s.镜像图误差和带宽限制的信息。
The W. M. Keck Observatory Ten-Meter Telescope (TMT) will be a high-performance astronomical telescope capable of unprecedented ground-based observations. One of the unique features of the TMT is its primary mirror which is composed of 36 hexagonal segments. A segment alignment control system will be used to achieve the optical quality of a glass monolith in the segmented primary mirror. The problems associated with the accurate pointing and imaging of a large flexible telescope such as the TMT are quite different from those posed by traditional rigid telescopes. These problems arise from two main sources: structural dynamic effects, such as enhanced sensitivity to external disturbances, and interactions between the segment alignment control system and the telescope structure. This study consists of a combined structural and control system analysis based upon mathematical models of the TMT structure, the segment alignment control system, and the aerodynamic loads on the primary mirror that are induced by the wind. Data for the structural model were derived from the most recent design iteration available during the time frame of the study. Actual wind velocities measured at three observatory sites were used to develop a generic model of the power spectrum of forces generated by wind loads. Information about the r.m.s. mirror figure errors and limits on the bandwidth of the control system as it is currently implemented are presented.