中国科学院机构知识库网格系统: 检索

Development of the depth-graded multilayers for XTP mission 会议论文 OAI收割
Space Telescopes and Instrumentation 2014: Ultraviolet to Gamma Ray, June 22, 2014 - June 26, 2014, Montreal, QC, Canada
作者: Wang Z.; Wang Z.; Wen M.

收藏 | 浏览/下载：15/0 | 提交时间：2015/04/27

Precision laser emission technology based on fast steering mirror for space optical communication 会议论文 OAI收割
2013 2nd International Conference on Measurement, Instrumentation and Automation, ICMIA 2013, April 23, 2013 - April 24, 2013, Guilin, China
作者: Sun T.

收藏 | 浏览/下载：11/0 | 提交时间：2014/05/15

A design method for time sequential synchronization of semi-physical simulation on guidance weapon system 会议论文 OAI收割
2013 2nd International Conference on Mechatronics and Control Engineering, ICMCE 2013, August 28, 2013 - August 29, 2013, Dalian, China
Jiang R. K.; Li D. W.; Cui L. Z.

收藏 | 浏览/下载：12/0 | 提交时间：2014/05/15

Research on Satellite Platform Vibration Compensation Method based on Liquid Crystal Steering System 会议论文 OAI收割
2012
作者: Wen M.

收藏 | 浏览/下载：4/0 | 提交时间：2013/03/28

Control of N/N2 species ratio in NO plasma for p-type doping of ZnO (EI CONFERENCE) 会议论文 OAI收割
作者: Chen X.; Liu L.; Liu L.; Li B.; Li B.

收藏 | 浏览/下载：14/0 | 提交时间：2013/03/25

Nitrogen-doped ZnO thin films were grown on c-plane sapphire (Al 2O3) substrates via plasma-assisted molecular beam epitaxy using plasma activated nitric oxide (NO) as the oxygen source and dopant. X-ray diffraction measurements indicate that a small NO flux benefits the crystal quality of the thin films. Hall effect measurements indicate that the electron density of the ZnO films decreases gradually with decreasing NO flux and the conduction reverses to p-type at a certain flux. Optical emission spectra indicate that the N atom content in the NO plasma increases with decreasing NO flux and the origin of this is discussed. X-ray photoelectron spectroscopy measurements demonstrate that the number of N atom occupied O sites in the ZnO lattice increases correspondingly. 2011 American Institute of Physics.

Thermal analysis on supersonic ellipsoidal dome (EI CONFERENCE) 会议论文 OAI收割
2nd International Conference on Multimedia Technology, ICMT 2011, July 26, 2011 - July 28, 2011, Hangzhou, China
Jiang Z.; Wei Q.; Jia H.

收藏 | 浏览/下载：20/0 | 提交时间：2013/03/25

Studied the transient thermal transfer analysis method due to a kind of supersonic ellipsoidal dome which is a conformal dome. Illuminated the principle of transient thermal transfer analysis. Accomplished the transient thermal analysis based on the model of ellipsoidal dome and studied the influence about the different material and the different velocity. Considered three materials consist of MgF2 Al2O3 and ZnS and meanwhile the velocity was Mach2.5 and the time consists of 10s 20s and 60s. The temperature initial loads were from FLUENT thermal simulation. The thermal conduction analysis and the thermal convection analysis were finished in software ANSYS in which the entire transient thermal analysis consists of modeling meshing element calculating and getting the results. The different temperature distributions based on varied time were gotten about the different materials. The results from analysis showed the temperature distribution of the structure of ellipsoidal dome which could help the following coupled thermal-structure analysis. 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：29/0 | 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.

Dynamic coupling analysis and modeling for stabilized platform of rolling-pitching 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: Liu H.; Liu H.; Liu H.

收藏 | 浏览/下载：8/0 | 提交时间：2013/03/25

Missile's attitude change will be delivered to visual axis through stabilized platform during maneuvering flight and the missile vibration will be an interference source to visual axis stabilization. In order to solve this problem the coupling relationship between missile attitude and visual axis is obtained by Coordinate transformation. When the seeker stably tracks a target the angular velocity of visual axis in inertial space is zero so the relative angular velocity of roll axis and pitch axis can be derived for servo control. According to Oura dynamics equation the dynamic models of roll axis and pitch axis were established and kinetic equations of two axises were obtained. The dynamic models can provide theoretical basis to developing research of servo control system and structural optimization design of stabilized platform. Finally some measures could reduce the dynamic coupling between the framework was given. 2011 IEEE.

Thermal-structure analysis of supersonic dome based on three materials (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
Jiang Z.; Ai X.; Wei Q.; Liu B.; Jia H.

收藏 | 浏览/下载：17/0 | 提交时间：2013/03/25

To a supersonic missile a seeker could enhance the aerodynamic ability due to decrease the resistance in flying. At the same time the primary function of a seeker has been considered as the most important equipment for a missile due to the importance for cueing of targets and tracking for the final approach. However the dome of a seeker which is made up of glass has poor mechanical performance. Especially in the higher altitude for a dome in which the aerothermal and pressure loads could destroy the structure easily it is necessary to do the thermal-structure coupled analysis due to varied materials. In the paper to take the spherical dome of a seeker as a example the analysis has been completed according to the varied materials consist of MgF2 Al2O3 and ZnS. The temperature loads and the pressure loads derived from the results of fluent analysis has been forced on the surface of dome which simulates the actual Mach 2.5 in flying. According to the results of coupled analysis the SEQV stress of the dome radium 80mm based on three materials had reached to 31MPa which shows that the strength is sufficient for Mach 2.5 and offered the warranty to design the attaching to missile for the dome. At the same time the results required the flexible mounting for the dome due to the displacements results which the crystal material couldn't accept. 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：23/0 | 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.