中国科学院机构知识库网格系统: 检索

Design and analysis of performance of FSO communication system based on partially coherent beams 期刊论文 OAI收割
OPTICS COMMUNICATIONS, 2020
作者: Wu, Yan; Mei, Haiping; Dai, Congming; Zhao, Fengmei; Wei, Heli

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收藏 | 浏览/下载：42/0 | 提交时间：2020/10/19

Free space optical communication Partially coherent beams Exponentiated Weibull turbulence Generalized pointing errors System performance parameters

Optical system design and measurement precision analysis of pointing mirror in solar hard x-ray imager 会议论文 OAI收割
Beijing, China, 2019-07-07
作者: Zhao, Jin; Yang, Jianfeng; He, Yinghong; Liu, Shengrun

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收藏 | 浏览/下载：238/0 | 提交时间：2020/03/04

solar hard X-ray imager pointing mirror optical system ghost analysis

Method and Implementation of Improving the Pointing Accuracy of an Optical Remote Sensor Using a Star Sensor 期刊论文 OAI收割
Traitement Du Signal, 2019, 卷号: 36, 期号: 4, 页码: 311-317
作者: Q.Liu; X.He; F.W.Guan; Y.C.Zhao; F.Jiang

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收藏 | 浏览/下载：46/0 | 提交时间：2020/08/24

star sensor,spatial optical remote sensor,external orientation,pointing accuracy,Computer Science,Engineering

Pointing error due to retroreflector array in compact common path/common mode adaptive optical system 期刊论文 OAI收割
OPTICS COMMUNICATIONS, 2012, 卷号: 285, 期号: 17, 页码: 3618-3622
作者: Huang, Jian; Xian, Hao; Li, Xiaofeng; Zhang, Peng; Jiang, Dagang

收藏 | 浏览/下载：29/0 | 提交时间：2015/07/10

Pointing error Common path/common mode adaptive optical system Retroreflector array Intensity distribution

Research on satellite platform vibration compensation method based on liquid crystal steering system (EI CONFERENCE) 会议论文 OAI收割
2011 SSITE International Conference on Future Material Research and Industry Application, FMRIA 2011, December 1, 2011 - December 2, 2011, Macau, China
作者: Wen M.

收藏 | 浏览/下载：22/0 | 提交时间：2013/03/25

This paper presents the disturbance compensation scheme based on liquid crystal steering system according to the problem that satellite platform vibration affects the tracking and pointing accuracy in space optical communication. The mathematical model of liquid crystal steering system is built. For improving convergence speed the adaptive controller based on posteriori estimation errors RLS lattice filter is designed which not only achieves fast adaptation but also reaches optimal steady-state disturbance compensation. Finally the simulation results show that this control scheme is valid and feasible. (2012) Trans Tech Publications Switzerland.

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

收藏 | 浏览/下载：40/0 | 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.

Effect of gimbal point displacement on optical axis pointing precision in an image seeker (EI CONFERENCE) 会议论文 OAI收割
2011 International Conference on Electric Information and Control Engineering, ICEICE 2011, April 15, 2011 - April 17, 2011, Wuhan, China
作者: Zhang X.; Zhang X.; Zhang X.

收藏 | 浏览/下载：39/0 | 提交时间：2013/03/25

A concentric glass spherical dome was usually chosen as the transparent window mounted in front of the optical lens in an image seeker. However optical ray had to change its direction when propagating through the dome due to refraction unless passing through the center of the dome which demanded gimbal point coincide with the center of the dome exactly. In fact gimbal point displacement could not be eliminating due to fabrication assembly and vibration therefore the optical axis pointing error generated. In this paper the effect of gimbal point displacement on optical axis pointing precision in an image seeker was analyzed and the theoretical expression of the optical axis pointing error was derived based on geometric optics and the error dynamics was explored by numerical. Take a visible light image seeker as a case the thickness of concentric glass spherical dome was 8mm and the inner radius was 72mm and the optical axis pointing errors varying dynamically with the look angle and the gimbal point displacement were shown in graph. When the gimbal displacement was 0.11mm the maximum optical axis pointing error was 0.054mrad that is equal to the instantaneous field of view (IFOV) corresponding to the camera system whose focal length was 120mm and pixel size was 6.5m. Furthermore with the gimbal displacement increasing the optical axis pointing error increased linearly. The analyzed results provided a theoretical basis for the displacement range which had to be limited strictly in the gimbal design process. 2011 IEEE.

Feed-forward control to stabilize optical axis based on accelerometer (EI CONFERENCE) 会议论文 OAI收割
2010 International Conference on Computer, Mechatronics, Control and Electronic Engineering, CMCE 2010, August 24, 2010 - August 26, 2010, Changchun, China
Wenfeng B.; Juan C.; Hu W.

收藏 | 浏览/下载：22/0 | 提交时间：2013/03/25

In the optoelectronic tracking system the azimuth and elevation system determine the pointing precision of the optical axis. We discuss how to stabilize the optical axis by apply the feed forward control based on the accelerometer output. Both the acceleration and speed are applied to the compound controller. The experimental results show that when the azimuth servo system works at maximum speed 50/s and maximum accelerate 30/s2 the maximum tracking error of the system is 1.08' with the feed forward compensation so the precision is increased 6 times compared to that of without compound control. 2010 IEEE.

Gimbal displacement error analysis on an electro-optical seeker (EI CONFERENCE) 会议论文 OAI收割
Optical Design and Testing IV, October 18, 2010 - October 20, 2010, Beijing, China
作者: Zhang X.; Zhang X.; Zhang X.

收藏 | 浏览/下载：38/0 | 提交时间：2013/03/25

It is essential to analyze the gimbal displacement errors for a seeker due to the importance for cueing of targets and tracking for the final approach. Otherwise for a seeker electro-driven with a concentric glass dome the large errors will decrease the picking pointing and tracking precision rooted from the displacement errors existing between the rotation center of the optical system and the gimbal. And the gimbaled camera system displacement errors are never eliminated but reduced due to the geometric errors consists of geometric tolerances of gimbal structure manufacture installation and vibration coming from working environment. In this paper the gimbal displacement errors in an electro-optically stabilized platform resulting from geometric errors and environment errors were analyzed and shown in detail. The mathematical modal of the gimbal displacement errors created based on multi-body dynamics demonstrated the connection between the gimbal displacement errors and the stabilized platform. Taking a visible light image seeker as a case the diameter is 120mm and the geometric tolerances came from the values of primary design and the vibration data came from the environmental vibration test on the pitch-yaw seeker and at the same time the errors resulting from installation were considered too. Based on calculating the maximum gimbal displacement error will reach to 0.2mm for pitching angle smaller than 40 and yawing angle smaller than 60. However the critical parts have been found out according to the probability theory and the reliability analysis successfully used in the paper and finally the maximum gimbal displacement error reduced to 0.1mm which is acceptable corresponding to the picking pointing and tracking precision for an optical imaging seeker. 2010 Copyright SPIE - The International Society for Optical Engineering.

A 3-axis simulator for spacecraft attitude control research (EI CONFERENCE) 会议论文 OAI收割
2010 IEEE International Conference on Information and Automation, ICIA 2010, June 20, 2010 - June 23, 2010, Harbin, Heilongjiang, China
作者: Dai L.

收藏 | 浏览/下载：34/0 | 提交时间：2013/03/25

This article presents the details of a new 3-axis simulator for spacecraft attitude control research and simulation. The air bearing allows the test bed to rotate about three axes with tiny friction. The attitude determination system consists of three fibre optical gyros an inclinometer and a magnetometer. The actuator of the system consists of three reaction flywheels and four control moment gyros (CMG). Mathematical models of the sensors and actuators are given to help algorithm design. An extended Kalman filter was designed to provide attitude information for controller. Mathematical simulation results prove the attitude determination system can achieve high precision. A coulomb friction model of reaction wheels is given with experimental results. A friction compensation algorithm was developed to raise the pointing accuracy of the control system. The article also describes the details of the hardware structure. A PD stabilizing controller is implemented to test the validation of the whole control system at last. 2010 IEEE.