scholarly journals Design and Optimization for Mounting Primary Mirror with Reduced Sensitivity to Temperature Change in an Aerial Optoelectronic Sensor

Sensors ◽  
2021 ◽  
Vol 21 (23) ◽  
pp. 7993
Author(s):  
Meijun Zhang ◽  
Qipeng Lu ◽  
Haonan Tian ◽  
Dejiang Wang ◽  
Cheng Chen ◽  
...  

In order to improve the image quality of the aerial optoelectronic sensor over a wide range of temperature changes, high thermal adaptability of the primary mirror as the critical components is considered. Integrated optomechanical analysis and optimization for mounting primary mirrors are carried out. The mirror surface shape error caused by uniform temperature decrease was treated as the objective function, and the fundamental frequency of the mirror assembly and the surface shape error caused by gravity parallel or vertical to the optical axis are taken as the constraints. A detailed size optimization is conducted to optimize its dimension parameters. Sensitivities of the optical system performance with respect to the size parameters are further evaluated. The configuration of the primary mirror and the flexure are obtained. The simulated optimization results show that the size parameters differently affect the optical performance and which factors are the key. The mirror surface shape error under 30 °C uniform temperature decrease effectively decreased from 26.5 nm to 11.6 nm, despite the weight of the primary mirror assembly increases by 0.3 kg. Compared to the initial design, the value of the system’s modulation transfer function (0° field angle) is improved from 0.15 to 0.21. Namely, the optical performance of the camera under thermal load has been enhanced and thermal adaptability of the primary mirror has been obviously reinforced after optimization. Based on the optimized results, a prototype of the primary mirror assembly is manufactured and assembled. A ground thermal test was conducted to verify difference in imaging quality at room and low temperature, respectively. The image quality of the camera meets the requirements of the index despite degrading.

2020 ◽  
Vol 59 (27) ◽  
pp. 8465
Author(s):  
Xiaotao Mi ◽  
Shanwen Zhang ◽  
Xiangdong Qi ◽  
Haili Yu ◽  
Hongzhu Yu ◽  
...  

2019 ◽  
Vol 215 ◽  
pp. 09004
Author(s):  
Haitao Liu ◽  
Fengtao Yan ◽  
Wenchuan Zhao ◽  
Jieli Wu ◽  
Min Zhou

Two silicon carbide (SiC) lightweight off-axis aspheric mirrors were fabricated by using robot polishing technology. One is a primary mirror with dimension 380mm×328mm, the other is a tertiary mirror with dimension 294mm×238mm. The robot polishing technology is the combination of CCOS technology and a 6-axises industrial robot. The setup of robot polishing system is discussed, and the mirror aspheric grinding, surface polishing and figuring process are reported in this paper. The final surface shape error of primary mirror is 11.4nm RMS, and the tertiary is 12.1nm RMS. The capability of off-axis aspheric mirror fabricating on robot polishing system is verified.


2013 ◽  
Vol 284-287 ◽  
pp. 2812-2815
Author(s):  
Ming Ying Hsu ◽  
W.C. Lin ◽  
Chia Yen Chan ◽  
C. F. Ho ◽  
S.T. Chang ◽  
...  

The telescope primary mirror Isostatic Mount (ISM) design is an important issue for optical performance. The ISM bonding position will affect the telescope performance. The primary mirror reflection surface is parallel with gravity force during telescope alignment process. Thus, the distance between ISM geometry center and primary mirror center of gravity will lead mirror surface deformation. The ISM mounting mainly aberration is astigmatism at mirror surface. This study is applied Finite Element (FEM) simulate mirror surface deformation and using Zernike polynomial fitting the mirror surface aberration. The simulation result show the ISM bonding at mirror neutral plane the aberration will minimum at 1G gravity. The ISM bonding position errors also affect aberration distribution.


2018 ◽  
Vol 10 (11) ◽  
pp. 3875 ◽  
Author(s):  
Adewumi Babafemi ◽  
Branko Šavija ◽  
Suvash Paul ◽  
Vivi Anggraini

The abundance of waste plastic is a major issue for the sustainability of the environment as plastic pollutes rivers, land, and oceans. However, the versatile behavior of plastic (it is lightweight, flexible, strong, moisture-resistant, and cheap) can make it a replacement for or alternative to many existing composite materials like concrete. Over the past few decades, many researchers have used waste plastic as a replacement for aggregates in concrete. This paper presents a comprehensive review of the engineering properties of waste recycled plastic. It is divided into three sections, along with an introduction and conclusion. The influence of recycled waste plastics on the fresh properties of concrete is discussed first, followed by its influence on the mechanical and durability properties of concrete. Current experimental results have shown that the mechanical and durability properties of concrete are altered due to the inclusion of plastic. However, such concrete still fulfills the requirements of many engineering applications. This review also advocates further study of possible pre-treatment of waste plastic properties for the modification of its surface, shape, and size in order to improve the quality of the composite product and make its use more widespread.


Author(s):  
Chuandong Chen ◽  
Jicai Liang ◽  
Yi Li ◽  
Ce Liang

In the flexible stretch bending of multi-point roller dies process, the deformation of workpiece is mainly driven by clamps. Therefore, the movement track of clamp has a great influence on the forming effect of workpiece. Y-profile, T-profile, and L-profile are taken as the research objects. Simulation and experiments are carried out with two different movement tracks. The influence of the movement tracks on shape error, springback error, and thickness variation of different profiles is discussed. The experimental results of the three profiles processed by the double-sided forming method are consistent with the simulation results, which proves the accuracy of the numerical simulation. The results show that the movement track has a great influence on shape error. Compared with double-sided forming, one-sided forming can effectively reduce springback error. The two different movement tracks have no obvious influence on thickness change.


2007 ◽  
Vol 51 (6) ◽  
pp. 1901 ◽  
Author(s):  
Yu-Deok Seo ◽  
Hyun-Jung Kim ◽  
Sung-Kie Youn ◽  
Seung-Hoon Lee ◽  
Deog-Gyu Lee ◽  
...  

2008 ◽  
Vol 28 (4) ◽  
pp. 756-763 ◽  
Author(s):  
谭凡教 Tan Fanjiao ◽  
乔彦峰 Qiao Yanfeng ◽  
李耀彬 Li Yaobin ◽  
高慧斌 Gao Huibin ◽  
刘旨春 Liu Zhichun

2003 ◽  
Author(s):  
Hermann Bittner ◽  
Matthias Erdmann ◽  
Peter Haberler ◽  
Karl-Heinz Zuknik

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