光学精密工程2011，Vol.19Issue(5)：1022-1029,8.DOI:10.3788/OPE.20111905.1022
620mm薄镜面的主动支撑结构及面形校正
Supporting structure of 620 mm thin primary mirror and its active surface correction
摘要
Abstract
In order to improve the surface precision of a thin primary mirror in a large aperture telescope at different altitude angles, the active correction procedure based on vibration modal calibration was proposed. For a thin primary mirror with the 620 mm in diameter, 18 mm in thickness and the axial taunting in 36 points for the active support, the lateral mounting in 6 tangent points for the passive support, the free vibration mode of primary mirror was analyzed by finite element method and the first 10 vibration modes of the primary mirror were calibrated. Their RMS values were unified to 1 000 nm, also the calibration forces were calculated. Furthermore,the surface of the primary mirror with different altitude angles was analyzed, the deformations were fitted by the modal vibration mode using least square method, and the corrective forces were calculated. Finally, the corrected surface precision and initiative surface precision were compared, and the fitted surface precision and remanent surface precision were analyzed after the second active correction. Corrected results demonstrate that the deformation (RMS) of the primary mirror is corrected from 27.64 nm to 12.95 nm while it is vertically positioned by using the maximum corrective force of 2.23 N, and from 7. 38 nm to 2.84 nm while horizontally positioned by using the maximum corrective force of 0.59 N. The simulation shows that the algorithm using modal vibration to actively correct the primary mirror surface is feasible.关键词
主动光学/薄镜面/面形校正/支撑结构/模态振型/最小二秉法/有限元Key words
active optics/ thin primary mirror/ surface calibration / supporting structure/modal vibration/ least square method/ finite element method分类
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陈夫林,张景旭,吴小霞,范磊..620mm薄镜面的主动支撑结构及面形校正[J].光学精密工程,2011,19(5):1022-1029,8.基金项目
中科院长春光学精密机械与物理研究所三期创新工程专项基金资助项目 （）
