Han Linchu, Liu Chengzhi, Fan Cunbo, Li Zhenwei, Zhang Jingxu, Yin Xiaolin
Appl Opt. 2018 Mar 1;57(7):1662-1670. doi: 10.1364/AO.57.001662.
A warping harness is proposed to simply and efficiently correct low-order aberrations that occur during manufacturing and operation of a telescope. For the Thirty Meter Telescope (TMT) tertiary mirror, the issue to be solved by the warping harness is particularly challenging due to its complicated load conditions and limited mounting space. In this study, first, a new type of whiffletree-based warping harness configuration applied to a ¼-prototype TMT tertiary mirror is presented and optimized using finite element analysis (FEA) to improve the output precision of the moment actuator. Next, based on the new configuration, a simulation method for a correction process is proposed. The results show that the root mean square value of the mirror-surface error converged from 64.9 to 25.4 nm after correction, which satisfied the requirement document of TMT. Finally, combined with the analysis and calculation results, the moment actuator testing system with high-precision displacement-force-strain is established to assess the system errors. The tests of the moment actuator displacement, stress, strain-output precision, linearity, and repeatability are completed, and all errors were found to be within a controllable range. The results show the validity and feasibility of the designed warping harness, which can prove its applicability in more complicated conditions and, to a certain degree, broaden the application scope of the warping harness.
提出了一种翘曲矫正装置，以简单有效地校正望远镜制造和运行过程中出现的低阶像差。对于三十米望远镜（TMT）的第三反射镜，由于其复杂的负载条件和有限的安装空间，翘曲矫正装置要解决的问题特别具有挑战性。在本研究中，首先，提出了一种应用于四分之一原型TMT第三反射镜的新型基于摇臂的翘曲矫正装置配置，并使用有限元分析（FEA）进行了优化，以提高力矩致动器的输出精度。接下来，基于新配置，提出了一种校正过程的仿真方法。结果表明，校正后镜面误差的均方根值从64.9收敛到25.4nm，满足了TMT的要求文件。最后，结合分析和计算结果，建立了具有高精度位移-力-应变的力矩致动器测试系统，以评估系统误差。完成了力矩致动器位移、应力、应变输出精度、线性度和重复性的测试，发现所有误差均在可控范围内。结果表明了所设计的翘曲矫正装置的有效性和可行性，这可以证明其在更复杂条件下的适用性，并在一定程度上拓宽了翘曲矫正装置的应用范围。
