中国开放科研知识云: 检索

Misalignment correction for free-form surface in non-null interferometric testing 期刊论文
Optics Communications, 2019, 卷号: 437, 页码: 204-213
作者: Z.M.Zang; D.Liu; J.Bai; Y.H.Zhou; T.L.Yan

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Free-form surface,Surface measurement,Figure,Interferometry,3-dimensional shape measurement,calibration,system,Optics

High-Resolution Angular Displacement Technology Based on Varying Moire Figure Phase Positions 期刊论文
Ieee Sensors Journal, 2019, 卷号: 19, 期号: 6, 页码: 2126-2132
作者: H.Yu; X.D.Jia; Q.H.Wan; L.H.Liang; C.H.Zhao

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Angular measurement,moire figure,phase difference,high resolution,optical encoder,sensor,Engineering,Instruments & Instrumentation,Physics

Computation of misalignment and primary mirror astigmatism figure error of two-mirror telescopes 期刊论文
Journal of Astronomical Telescopes Instruments and Systems, 2018, 卷号: 4, 期号: 1, 页码: 10
作者: Gu, Z. Y.; Wang, Y.; Ju, G. H.; Yan, C. X.

收藏 | 浏览/下载：6/0 | 提交时间：2019/09/17

active optics alignment misalignments astigmatic figure error nodal aberration theory two-mirror telescope 5th-order optical aberrations rotational symmetry wave-front systems collimation Engineering Instruments & Instrumentation Optics

Structural design of primary mirror subassembly for space telescope (EI CONFERENCE) 会议论文
2nd International Conference on Mechatronics and Applied Mechanics, ICMAM 2012, December 8, 2012 - December 9, 2012, Taiwan
Xu H.

收藏 | 浏览/下载：46/0 | 提交时间：2013/03/25

In order to design a large aperture primary mirror with the diameter of 1150 mm the parameters impacting on gravity deformation of the mirror were analyzed and discussed in detail including material selection diameter-thickness ratio the number of the support points location selection and lightweight structure etc. A novel space mirror structure system was put forward and its back was opened and supported by six points on back. The dynamic and static and thermal characteristics were analyzed based on the finite element method. Analysis results showed the surface figure accuracy reached to RMS 14.5nm under the action of gravity load along the optical axis direction and the first-order natural frequency was 214Hz which met to the designed indexes requirements. (2013) Trans Tech Publications Switzerland.

Optimization analysis for radial support by finite elements method (EI CONFERENCE) 会议论文
2012 International Conference on Intelligent System and Applied Material, GSAM 2012, January 13, 2012 - January 15, 2012, Taiyuan, Shanxi, China
Li C.; Wang Y.

收藏 | 浏览/下载：16/0 | 提交时间：2013/03/25

Primary mirror' surface figure is affected by supporting structure obviously. Especially for large-aperture telescope the surface figure is significant because of primary mirror' self-weight. For the requirement of the usage it's necessary to minimize the surface figure from self-weight by reasonable supporting scheme. The text optimized support point and force of radial support to minimize the surface figure by finite-element software. At the same time it studied the relationship between support point and counterweight to reduce the weight of support structure. At last it gave the optimal solution. (2012) Trans Tech Publications.

Design and test of pointing mirror assembly for spaceborne remote sensing camera (EI CONFERENCE) 会议论文
2011 International Conference on Electronics, Communications and Control, ICECC 2011, September 9, 2011 - September 11, 2011, Ningbo, China
Chen W.; Ding Y.; Hui S.

收藏 | 浏览/下载：31/0 | 提交时间：2013/03/25

In order to ensure the surface figure of the pointing mirror (460mm long 290mm wide) in spaceborne remote sensing camera Silicon Carbide was selected as the mirror material. The form of composite triangular and rectangular and the combination of open and closed back was explored in the lightweight design. A new kinematic mount and flexible structure in axis is used to hold the mirror around the lateral surface. The structure can minimize distortions induced by coefficient of thermal expansion mismatch among the materials. This eliminates the bending of the integral mount under the weight of the mirror. Optical performance of the mirror was analyzed under gravity load and temperature load using finite element method. Predicted surface figure error based on the removal of bias tilt and power was calculated using an in-house Matlab script for mirrors. The pointing mirror assembly was tested using open loop servo control. And the surface figure was checked using interferometer. Surface figure accuracy is better than 1/30 ( 632.8nm rms). The results show that the kinematic mount induces minimal figure error on the optical surface. 2011 IEEE.

The Research of real time auto-recognition of the moire fringe (EI CONFERENCE) 会议论文
International Symposium on Photoelectronic Detection and Imaging 2011: Advances in Imaging Detectors and Applications, May 24, 2011 - May 26, 2011, Beijing, China
Wang M.-J.; Wu Z.-G.

收藏 | 浏览/下载：15/0 | 提交时间：2013/03/25

Measuring the movement of raster by the method of moire fringe has the advantage of high sensitivity high resolution and non-contacted measurement. The characteristic of moire fringe is that the image is white alternate with black the angle of the stripes is uniform the width of the stripes is uniform the terminators of the stripes aren't clear. A fast method that can figure out the width and angle of the moire fringe precisely is put forward in this paper. It calculates the angle the stripes firstly. According to the principle of the minimum mean squared error (MMSE) the closer a series of data is the smaller the value of the MMSE will be. The method is described as follows: It takes the image's center as the origin 180 beelines pass through the origin with the same angle interval. it calculates the value of the minimum mean squared error of the 180 beelines and find out the least one among those then the angle of the moire fringe comes out primarily. In order to improving the calculating precision of moire fringe 60 equal angles are divided in the neighborhood of the angle then a precise angle of moire fringe is calculated according to the principle of the MMSE. After getting out the angle of the moire fringe we begin to calculate the width of moire fringe. A line vertical with the moire fringe is drawn and we can get the width of the moire fringe by the vertical line. In order to get over the influence of the noise an effective area with the shape of diamond is selected in the image. The data of area is accumulated and projected according to the direction of moire fringe and a sine curve come out. The width of moire fringe can be obtained by getting the position of the first wave crest the position of the last wave crest and the number of wave crest. Experiments prove that the precision of the method put forward in this paper is enhanced in comparison with the traditional frequency method the precision of width calculation achieves to 99.6% according to the evaluation indicators of width detection error. The computing speed is boosted largely compared with traditional method and it can achieve with 15 ms that satisfying the demand of real time. 2011 SPIE.

Brazing RB-SiC used in large aperture space optical system (EI CONFERENCE) 会议论文
2011 International Conference on Materials and Products Manufacturing Technology, ICMPMT 2011, October 28, 2011 - October 30, 2011, Chengdu, China
Zhang B.; Zhang Z.

收藏 | 浏览/下载：17/0 | 提交时间：2013/03/25

Because of the sic material's superior optical characteristic machine characteristic and hot characteristic it becomes currently the space big aperture reflector choose firstly1. For larger aperture sic mirror it is not economical and safe to make the monolithic body directly 2 3. The SiC mirror brazed assembly with several segments can solve these problems. In this paper one 600 mm sic plane mirror as demonstration welded with 3 radial segments is roughly grinded to the required figure at first then the mirror is finely grinded and polished by the technology of CCOS the mirror figure error is less than 1/20 ( = 632.8nm) in RMS finally. The problems of the preferential removal near braze joint are solved. The methods of reducing the residual stress of mirror are discussed. At last some measurements and experiments are carried on and the results conclude that the brazed SiC mirror can meet the requirement of large aperture optical systems. (2011) Trans Tech Publications.

The analysis of the large-diameter primary mirror deformation of surface figure in the temperature field (EI CONFERENCE) 会议论文
2010 International Conference on Computer, Mechatronics, Control and Electronic Engineering, CMCE 2010, August 24, 2010 - August 26, 2010, Changchun, China
Feng S.-L.

收藏 | 浏览/下载：11/0 | 提交时间：2013/03/25

The effect on the deformation of the primary mirror surface figure of the temperature gradient has been discussed theoretically. And its effect under axis and radial temperature gradient is analyzed when optical axis and support ways of the mirror changed. It has been concluded that the effect on the surface figure of the axis gradient is larger than radial gradient and also found that the deformation is concerned not only with thermal and structural parameter but also directly with the magnitude and direction of the temperature gradient. 2010 IEEE.

The design of missile's dome that fits both optical and aerodynamic needs (EI CONFERENCE) 会议论文
5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Smart Structures and Materials in Manufacturing and Testing, April 26, 2010 - April 29, 2010, Dalian, China
Wei Q.; Zhang X.; Jia H.

收藏 | 浏览/下载：10/0 | 提交时间：2013/03/25

Optical guidance missiles requires a dome which fits both optical and aerodynamic needs when they attack at 3 Ma. In this study ellipse is the figure chosen to be the dome's shape. The ellipticity is the main variable should to be decided. The optimized function was built by optical and aerodynamic performance function multiply by their weights. The optical and aerodynamic functions were all obtained by computational fluid dynamic (CFD) simulation's results after normalization. In this study the optical and aerodynamic performances have equal weights after optimzing the ellipticity is 2 for the missile. 2010 SPIE.

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