红外与激光工程, 2016, 45(5): 0517003, 网络出版: 2016-05-01
TMT tertiary mirror dynamical model measurement and modification
1中国科学院长春光学精密机械与物理研究所, 吉林 长春 130033
2中国科学院大学, 北京 100049
为了更好地对于30 m望远镜三镜(TMT M3)的动力学进行度量与检测, 基于加速度信号建立了系统模态信息的计算与评价方法。首先, 分析了如何利用加速度计对于TMT三镜系统进行检测。之后, 利用系统对于未知载荷的响应, 基于随机减量法获得了系统的自由响应;之后, 根据多项式拟合的方法, 对于获得的传递函数进行处理。根据之前所提出的方法, 对于4 m级系统, 获得了其系统前两阶模态为88 Hz以及107 Hz, 并获得了对应振型。所做的工作对于TMT三镜的完成有着很好的指导作用。
To measure the dynamic performance of the thirty meter telescope tertary mirror, the model based on the accerleration signal was established for parameters calculation and identification. First and foremost, under the TMT requirement, the procedure to obtian the dynamic property of the system by acceleration signal was presented. Then, by the output to the unknown excitation, the free response can be reached. After that, the polynomials fitting was used to process the transfer function obtained from the previous step to identify the model parameters. This method was then applied to a four-meter scale system, the first two orders of strcture were correspondingly 88 Hz and 107 Hz. What is more, the mode shape is also calculated and the parameters in the modle are modified by it. The work of this artile is expected to be helpful for the accomplishent of the thirty meter telescope.