GSSM系统抖动测量误差分析

发布时间：2019-05-06 21:43

【摘要】：30 m望远镜三镜是世界上最大的平面镜,由于其复杂的功能,又被称作大型科学可控反射镜(Giant Steering Science Mirror,GSSM)。为了更好地分析与抑制GSSM在实现光线中继功能时的抖动,需要对抖动有精确的测量。由于GSSM抖动的要求特殊且严格,在测量之前,需要对抖动测量的误差进行仔细地分析与理解,才可以更好地完成检测任务。首先,文中针对使用编码器进行抖动测量的情况,在不同的测量方案以及相对距离下,通过蒙特卡洛方法可以得到由激光跟踪仪进行标定的误差:俯仰轴线的定位误差,在轴上测量的期望为1μm,小于轴外测量的3μm;方位轴线的定位误差在激光跟踪仪偏离两米的情况下为4.6μm。之后对加速度计测量抖动的误差进行了考虑,首先推导了使用功率谱方法的完备性条件;之后使用累积功率谱对于333B32的标定结果进行处理,得到当采样频率为2 048 Hz,0.05 Hz以外的频段,其精度为0.6μm。抖动的测量以及误差分析,不仅是GSSM建设过程中十分重要的环节,同时,它可以为大口径望远镜建设提供宝贵的统计学先验知识,并对于系统工程的发展是一种很好的推动。
[Abstract]:The three-mirror of 30 m telescope is the largest planar mirror in the world. Because of its complicated function, it is also known as the large-scale scientific controllable mirror (Giant Steering Science Mirror,GSSM). In order to better analyze and suppress the jitter of GSSM in the realization of ray relay function, it is necessary to measure the jitter accurately. Because of the special and strict requirements of GSSM jitter, it is necessary to analyze and understand the error of jitter measurement carefully before measuring, so that the task of detection can be completed better. Firstly, aiming at the jitter measurement using encoder, the calibration error of laser tracker can be obtained by Monte Carlo method under different measurement schemes and relative distance: the positioning error of pitch axis, The expectation of measurement on the axis is 1 渭 m, which is less than 3 渭 m measured outside the axis. The orientation error of the azimuth axis is 4.6 mm when the laser tracker deviates from two meters. After that, the error of accelerometer measurement jitter is considered. Firstly, the completeness condition of using power spectrum method is deduced. Then the calibration results of 333B32 are processed by using cumulative power spectrum. When the sampling frequency is not 2048 Hz,0.05 Hz, the precision is 0.6 mm. The measurement of jitter and error analysis are not only very important links in the process of GSSM construction, but also can provide valuable statistical prior knowledge for the construction of large aperture telescopes, and it is a good impetus to the development of system engineering.
【作者单位】：中国科学院长春光学精密机械与物理研究所;中国科学院大学;
【基金】：国家自然科学基金(11403022)
【分类号】：TH751

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