Frequency response of imaging quality by micro-vibration for large-aperture space-borne telescope

2016 ◽  
Vol 24 (5) ◽  
pp. 1118-1127 ◽  
Author(s):  
朱俊青 ZHU Jun-qing ◽  
沙 巍 SHA Wei ◽  
陈长征 CHEN Chang-zheng ◽  
张星祥 ZHANG Xing-xiang ◽  
任建岳 REN Jian-yue
Keyword(s):  
Frequency Response ◽  
Imaging Quality ◽  
Large Aperture ◽  
Micro Vibration

Iterative feedback control based on frequency response model for a six-degree-of-freedom micro-vibration platform

2021 ◽  
pp. 107754632199731
Author(s):  
He Zhu ◽  
Shuai He ◽  
Zhenbang Xu ◽  
XiaoMing Wang ◽  
Chao Qin ◽  
...  
Keyword(s):  
Feedback Control ◽  
Frequency Response ◽  
Control Strategy ◽  
Degree Of Freedom ◽  
Small Displacement ◽  
Response Model ◽  
Parameter Uncertainties ◽  
Micro Vibration ◽  
Six Degree Of Freedom ◽  
Iterative Feedback

In this article, a six-degree-of-freedom (6-DOF) micro-vibration platform (6-MVP) based on the Gough–Stewart configuration is designed to reproduce the 6-DOF micro-vibration that occurs at the installation surfaces of sensitive space-based instruments such as large space optical loads and laser communications equipment. The platform’s dynamic model is simplified because of the small displacement characteristics of micro-vibrations. By considering the multifrequency line spectrum characteristics of micro-vibrations and the parameter uncertainties, an iterative feedback control strategy based on a frequency response model is designed, and the effectiveness of the proposed control strategy is verified by performing integrated simulations. Finally, micro-vibration experiments are performed with a 10 kg load on the platform. The results of these micro-vibration experiments show that after several iterations, the amplitude control errors are less than 3% and the phase control errors are less than 1°. The control strategy presented in this article offers the advantages of a simple algorithm and high precision and it can also be used to control other similar micro-vibration platforms.

Optical Design of Very Large Four-Mirror Systems

2007 ◽  
Vol 364-366 ◽  
pp. 1231-1236 ◽  
Author(s):  
Li Rong Zhu ◽  
Wei Min Shen
Keyword(s):  
Focal Length ◽  
Optical Design ◽  
Diffraction Limit ◽  
Field Of View ◽  
Initial Structure ◽  
Entrance Pupil ◽  
Primary Mirror ◽  
Imaging Quality ◽  
Large Aperture ◽  
Design Idea

Four-mirror systems with a very large aperture and a long focal length were investigated and designed. Their design idea is given. Through the derivation of primary aberration formula, the aberration properties were analyzed and discussed, and the method to determine its initial structure is reported. As examples, two four-mirror systems with spherical and parabolic primary mirror, 100m focal length, and 10m entrance pupil were optimally designed. Their imaging quality approaches diffraction limit within field of view of 0.4 and 0.5 degrees respectively.

Research on the Support and Gravitational Deformation of Large Aperture Primary Mirror of Space Telescopes

2012 ◽  
Vol 516 ◽  
pp. 181-185
Author(s):  
Yang Lin Peng ◽  
Yi Fan Dai ◽  
Shan Yong Chen
Keyword(s):  
Body Motion ◽  
Space Telescopes ◽  
Key Factors ◽  
Support Design ◽  
Element Analysis ◽  
Primary Mirror ◽  
Imaging Quality ◽  
Large Aperture ◽  
Support Methods ◽  
Surface Figure

The surface figure of the primary mirror in a large aperture telescope is one of the key factors influencing imaging quality. Space telescopes are used in weightless environments, which is different from the ground environment for optical machining and testing. Therefore the effect of the deformation induced by gravity on the imaging quality is not negligible and the mirror support is to be carefully designed to unload the gravity during the course of machining and testing. In this paper, finite element analysis software is adopted to simulate and compare the deformation induced by gravity of a metre-scale aspheric lightweight primary mirror with different support methods and different working conditions. The results are then imported into MetroPro software supplied by ZYGO Corporation, to remove the tilts and rigid body motion of the mirror and calculate the primary aberrations from the deformation. Finally, sensitivity analysis of support deformation is implemented and the principles of mirror support design are summarized. The research is instructive for design, machining and testing of large aperture mirrors.

scholarly journals Frequency response of large aperture oxide-confined 850 nm vertical cavity surface emitting lasers

2009 ◽  
Vol 95 (13) ◽  
pp. 131101 ◽  
Author(s):  
A. Mutig ◽  
S. A. Blokhin ◽  
A. M. Nadtochiy ◽  
G. Fiol ◽  
J. A. Lott ◽  
...  
Keyword(s):  
Frequency Response ◽  
Cavity Surface ◽  
Large Aperture ◽  
Surface Emitting Lasers ◽  
Vertical Cavity Surface ◽  
Emitting Lasers ◽  
Vertical Cavity
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