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浏览/检索结果: 共4条，第1-4条 帮助 已选(0)清除 条数/页：5101520253035404550556065707580859095100   排序方式：请选择作者升序作者降序题名升序题名降序发表日期升序发表日期降序提交时间升序提交时间降序 Effect of gimbal point displacement on optical axis pointing precision in an image seeker (EI CONFERENCE) 会议论文 2011 International Conference on Electric Information and Control Engineering, ICEICE 2011, April 15, 2011 - April 17, 2011, Wuhan, China Zhang X.; Jiang Z.; Wei Q.; Jia H. 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.   Thermal-structure analysis of supersonic dome based on three materials (EI CONFERENCE) 会议论文 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 Optical Design and Testing IV, October 18, 2010 - October 20, 2010, Beijing, China Jiang Z.; Zhang X.; Ai X.; Wei Q.; Jia H. 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.   Equivalent lenses of supersonic seeker's outflow refractive index field obtained by simulation and experiment (EI CONFERENCE) 会议论文 2008 International Conference on Optical Instruments and Technology: Optical Systems and Optoelectronic Instruments, November 16, 2008 - November 19, 2008, Beijing, China Qun W.; Hongguang J.; Ming X. 收藏  |  浏览/下载：18/0  |  提交时间：2013/03/25 In order to decrease the aerodynamic drag of supersonic image guide missile and design a non-spherical dome  the outflow field of the missile's dome is simulated using FLUENT. Based on the simulated results  the accurate density field of the outflow field at all kinds of flight conditions is obtained  and then the refractive index field of the outflow field is gotten according to the Gladstone-Dale law. The results show that the shock wave induces the heterogeneity of the refractive index field and the turbulent causes distortion. The outflow field is divided into several zones which are taken as equivalent lenses for aberration analysis. 2009 SPIE.