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	Pointing design and testing of corner reflector 会议论文 OAI收割 Xiamen, PEOPLES R CHINA, 2020-08-25 作者: Liu Jie; Wang Hu; Lin Shangmin; Xue Yaoke; Liu Yang \| 收藏 \| 浏览/下载：20/0 \| 提交时间：2021/06/04 Pointing design corner reflector corner cube prism
	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.
	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：37/0 \| 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：33/0 \| 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.
	Orientation error analysis of alt-alt photoelectric telescope (EI CONFERENCE) 会议论文 OAI收割 4th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Large Mirrors and Telescopes, November 19, 2008 - November 21, 2008, Chengdu, China 作者: Wu X.-X. 收藏 \| 浏览/下载：37/0 \| 提交时间：2013/03/25 In order to ascertain the effects of main errors of alt-alt photoelectric telescope on measurement accuracy orientation error is analyzed.For analyzing optical mechanical and electrical errors from measured target to telescope picture we construct 7 coordinates such as:the earth's core coordinate alt-alt coordinate etc. carry through 21 times coordinate transformation form measuring equation with 26 variables. and we utilize Monte Carlo method to calculate the orientation error analyze the effects of errors upon pointing. The result indicates that the measuring error standard deviation of alt-alt telescope is minimum value about 10? at the zenith zone. and the deviation increases with the rotation angles of longitude and latitude axes. The model and the method not only can analyze and synthesize the main errors but also provide a reference to the whole design. 2009 SPIE.
	Research on 10.6 m laser beam monitoring in CO2 laser processing system (EI CONFERENCE) 会议论文 OAI收割 Infrared Materials, Devices, and Applications, November 12, 2007 - November 15, 2007, Beijing, China 作者: Gao Y.; Shao S. 收藏 \| 浏览/下载：30/0 \| 提交时间：2013/03/25 It is a key point of CO2 laser beam monitoring in the CO 2 laser processing system to achieve alignment between CO2 laser and PL (pointing and launching) system. By monitoring the angle offset of CO2 laser beam the compensation can be gotten witch is given to fast-steering mirror to rectify the direction of laser beam. But the normal photoelectric detector can not get the laser signal because of CO2 laser's high energy and long wavelength. Its wavelength is 10.6m and its power can reach kW level. Consequently it is difficult to detect the high-energy 10.6m laser beam directly. So we monitored the output mirror of laser resonator superseded the laser beam indirectly. The laser beam monitoring system could be designed based on CCD laser auto-collimation angular measurement principle and image processing method. In this paper application of CCD laser auto-collimation angular measurement principle and image processing method for CO2 laser beam monitoring system is introduced particularly After design fabrication and alignment the monitoring system can be used for experimental study that including angular measurement accuracy and angle offset measurement of CO2 laser beam. Angle offset range and angle variation rule of CO2 laser beam is also can be acquired for further research.