【作者】 孙向阳；

【导师】 张国玉；

【作者基本信息】 长春理工大学 ， 仪器科学与技术， 2013， 博士

【摘要】 光学导航敏感器是利用其光学系统将不同空间目标成像于光电探测器靶面,通过数字处理技术得到数字图像,提取标准目标表后,再利用姿态计算单元得到飞行器导航需要的星体中心矢量、运行轨道高度以及其惯性姿态,从而实现对卫星等航天器的精确导航,所以光学导航敏感器在地面上标定试验的精度,将直接关系到航天器在轨工作精度。而目前国内外地面标定所采用的方法精度只能到达10"左右,不能满足深空导航敏感器对星间角距精度≤1"的标定要求。通过分析已有常规标定系统在高精度光学敏感器标定时存在的技术缺点,展开对深空导航敏感器标定系统及其关键技术的研究,提出一种高精度光学导航敏感器标定方法,并设计出可实现星间角距精度≤1",5～10等星准确模拟的深空导航敏感器标定系统,可为深空导航敏感器提供高精度静态可变标准星图,解决了目前常规标定设备的工作性能无法满足深空导航敏感器标定的现实问题。论文提出了深空导航敏感器标定系统的总体方案,论述了标定系统的总体组成,并阐述了标定系统的工作原理。本文研究的标定系统由动态小天体全视场高精密模拟器和高精度大口径静态可变目标标准源两部分组成。模拟器采用了透射式长焦距大视场投影光学系统,以达到全视场全光谱范围内波差、倍率色差与畸变等像差要求。目标标准源以OLED、光纤以及自聚焦透镜组合的光耦合机构作为照明系统,配合高精密靶标进行星图模拟的方案。标定系统的工作原理是用模拟器接收目标标准源通过变换星点位置和亮度形成的不同星图,再按照敏感器视场形成无限远的可变标准模拟星图,投射到敏感器入瞳处,实现在地面上模拟出敏感器在太空中看到的不同星相图。本文在给定的标定系统光学系统的基础上,着重对标定系统的机械机构进行了详细设计。针对长焦距的机械结构特点以及目标源弱目标模拟要求,系统设计了自准直调焦机构来确保目标源位于光学系统的理论焦平面处；同时为了减小系统整体尺寸,光路配置有转向平面反射镜,其采用了微应力装夹方法,以消除由反射镜变形和外界振动时所造成的光线偏移与跳动；为了方便装调和减少因整体结构过大而易受外界振动影响,系统采用分段式结构,并通过软连接进行拼装。对大尺寸、高精度星模拟器光机结构的关键技术进行了研究。首先提出一种光机结构的轴向一致性可控方法,通过分析不同结构尺寸的挠曲构件温度变化下的轴向变形量,来建立挠曲构件的参数方程式,解算方程可得到具体参数大小,并以此实现用于大尺寸光学透镜系统的挠曲元件的合理设计。此方法的应用可消除或减弱光学元件与装配零件相对移位或变形时对光学元件造成的应力破坏,保持所设计光学系统的光学特性一致。同时也研究了大尺寸棱镜运动学和半运动学的安装方法,分析几种不同的棱镜安装结构对棱镜光学特性的影响,给出了标准安装时的计算公式,并对自准直调焦机构中的大尺寸分光棱镜安装机构进行了半运动学设计。提出了高精度大口径静态可变目标标准源的总体方案,即将OLED面阵光源、光纤传光束与高精度星点靶集成实现星图模拟。此方法实现了在高精度光学敏感器标定时,对模拟星图中,星间角距与星等的高精度标定要求,其具有的宽星等范围的模拟技术,为深空探测用敏感器的进一步研究提供了技术支持。详细设计了目标标准源的的照明系统。通过研究光源与光纤的耦合技术,分析影响耦合效率的主要因素,给出目标标准源照明系统设计方案；对比已有光源与光纤的耦合方式,结合标定系统中光学系统能量损耗的计算结果以及耦合机构技术参数,选择OLED作为目标标准源的光源与聚合物光纤和自聚焦透镜构建成目标源照明系统,实际设计与仿真结果表明此照明系统可提供5～10等星的准确星亮度,并能够实现单星精确可控。分析了标定系统的关键参数星间角距和星等的精度影响因素,并提出了检测方法,实测结果表明其星间角距精度≤1",模拟星等范围5～10等,可满足深空导航敏感器标定的精度要求。更多还原

【Abstract】 Optical navigation sensor is the special equipment of the precise navigation for the aircraft. Using of the optical system of navigation sensor, the photoelectric detector target surface can obtain the different imaging of the space target. Through the digital processing technology of digital image, the attitude calculation unit of navigation sensor can obtain the quasar center vector, orbit height and inertial attitude used for the aircraft navigation by the extraction of standard target table. Through the above operation can achieve the precise navigation of the satellite spacecraft. So it is so important to the optical navigation sensor that we must to calibrate the optical navigation sensor to get the precision value of the navigation sensor on the ground before the actual operation. At present the precision of the ground calibration using in the domestic and foreign methods can reach10" or so,which cannot meet the calibration requirement to deep space sensor that the star included angle accuracy is≤1".By analyzing the technical shortcomings using the existion conventional calibration system in the high precision optical sensor calibration,we research the the deep space navigation system and its technology,and put forward a new kind of the calibration method of the high precision optical sensor.Finally,we design the sensor calibration system based on the above presented method can realize the star included angle accuracy≤1",the magnitude5～10.The designed calibration system can simulates the high precision static variable standard star map,so the practical problem that the conventional calibration equipment performance cannot meet the calibration to the ddp space navigation sensor.We present the overall scheme of calibration system of deep space navigation sensor in this paper,and then constrcures and the principle of the calibration system are introduced.The calibration system is mainly composed of the high precision parallel light pipe and the high precision star charts simulator. In order to achieve the precision of the wave aberration, chromatic difference of magnification and distortion on the full field of view and the full spectral range, the simulator uses in the long-focal distance, large field projection optical system. The star charts simulator is introduced based on the method that combing the lighting system using the OLED,optical fiber and self-focusing lens as the optical coupling mechanism with the high-precision target. The work principle of the designed calibration system is that the simulator receives the different star map through the changing the star position and brightness, and projects the infinite variable standard star map to the entrance pupil of the sensor in accordance with the size of the sensor field, such realizing the different astrological charts in space to the sensor on the ground.We detailed design the mechanical mechanism of the calibration system based on the designed optical system.In view of the simulation requirements of the long focal length mechanical structure features and the weak target simulation,the collimation focusing mechanism is designed to ensure the target source located in the theory focal plane of the optical system.At the same time in order to reduce the overall system size,the steering mirror,which designed using of the micro stress clamping method to elimination the light shift and beating resulted from the reflector deformation and the vibration, is fixed in the system optical path.The overall sectional structures are connected by soft connection to facilitate the assembly and reduce the vibration influence because of the large strcture.Studying the key technology about the machine structure of the large size, high-precision star simulator, The controllable axial conformity for opt-mechanical structure is put forward, which shows using the designed flexure member can eliminated or attenuated the stress damage to optical element when the relative displacement of the components or the deformation caused by the temperature change. The parametric equation is established through analysis of the interrelation between the deformation of the different structure dimensions flexural member and the temperature change, and the parameters solving method is given too. Study on the installation method of the large size prism based on the kinematics and the semi dynamic and analysis of the influence of the optical properties of the prism under the difference installation structure on the prism,we present the calculation formula of the standard installation. Applying the above theory,the collimation focusing mechanism is designed.The overall scheme of star charts simulator, which is based on the optical coupling technology through the OLED combing with fiber and high-precision star target, is presented. Applying this scheme, the calibration system can achieve the high-precision calibration parameters including the star included angel, star brightness. This simulation technology having a wide range of magnitude value provides technical support for the further study on the deep space detection sensor.The lighting system of star charts simulator is detailed designed. Through research the coupling technology and analysis of the main effecting factors to the coupling efficiency, the scheme of the lighting system is presented. We choose the OLED as source, the polymer optical fiber and self-focusing lens to constructed the lighting system through comparison with several coupling methods and combing with the calculation results of energy loss of the optical system and the technical parameters of the coupling mechanism. The actual design and the simulation results show that the lighting system can provide5～10star brightness and realize the single star accurately controlled.Analysis of the key parameters of the calibration system mainly including the star included angle precision and the magnitude precision, we put forward theirs detection methods. The actual test results that star included angle accuracy<1",5～10magnitude simulation proves that the studied optical sensor calibration system meet the calibration precision of the current deep space navigation sensor.更多还原