CN106441281A - Small high-precision star sensor with long service life - Google Patents
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Abstract
一种小型长寿命高精度星敏感器，包括遮光罩、光学系统、机械结构、图像传感器电路、控制与数据处理模块、姿态计算模块；遮光罩遮挡直射光线或反射光线进入光学系统，光学系统采集导航恒星能量并送至图像传感器电路，图像传感器电路对导航恒星星点能量成像得到数字导航恒星星图，控制与数据处理电路提取导航恒星星图中星点的有效像元后进行伪星判别、剔除，得到导航恒星星点，姿态计算模块对导航恒星星点与星表进行匹配识别得到导航恒星姿态数据，机械结构支撑和固定遮光罩、光学系统、图像传感器电路、控制与数据处理模块、姿态计算模块。
A small, long-life and high-precision star sensor, including a light hood, an optical system, a mechanical structure, an image sensor circuit, a control and data processing module, and an attitude calculation module; the light hood blocks direct light or reflected light from entering the optical system, and the optical system collects The energy of the navigation star is sent to the image sensor circuit, and the image sensor circuit images the energy of the star point of the navigation star to obtain a digital navigation star map, and the control and data processing circuit extracts the effective pixel of the star point in the navigation star map to perform false star discrimination, Eliminate to obtain the star point of the navigation star, and the attitude calculation module matches and recognizes the star point of the navigation star and the star catalog to obtain the attitude data of the navigation star, the mechanical structure supports and fixes the hood, the optical system, the image sensor circuit, the control and data processing module, the attitude computing module.
Description
技术领域technical field
本发明涉及空间飞行器用恒星敏感器领域，特别是一种小型长寿命高精度星敏感器。The invention relates to the field of star sensors for space vehicles, in particular to a small, long-life and high-precision star sensor.
背景技术Background technique
随着空间技术的发展，航天器的指向精度有了越来越高的要求，姿态测量敏感器是卫星高精度和高稳定度的重要保证，而星敏感器是卫星控制系统中比较重要的姿态测量敏感器。星敏感器应用范围广泛，以天空中的恒星作为观测基准，是现阶段精度最高的姿态测量敏感器，其姿态的测量精度可达角秒级甚至更高，具有精度高、重量轻、功耗低、无漂移和工作方式多等优点。With the development of space technology, the pointing accuracy of spacecraft has higher and higher requirements. The attitude measurement sensor is an important guarantee for the high precision and high stability of the satellite, and the star sensor is a relatively important attitude in the satellite control system. measurement sensor. The star sensor has a wide range of applications. Taking the stars in the sky as the observation reference, it is the attitude measurement sensor with the highest precision at this stage. The measurement accuracy of its attitude can reach the arc-second level or even higher. Low, no drift and many working methods and other advantages.
传统的星敏感器典型技术指标为：重量3～5kg、高精度5～10＂、动态性能1°/s、数据更新率5～8Hz、初始捕获时间10～20s、工作寿命5～8年。而现阶段任务型号对星敏感器技术指标需求为：重量2kg左右、高精度3＂、动态性能3°/s、数据更新率10Hz、初始捕获时间1s、工作寿命15年，现有的星敏感器由于其在探测器灵敏度较低和电路噪声较大、大视场大孔径光学系统的像质不高、遮光罩杂光抑制较弱、结构稳定性较差等原因导致产品在小型化方面，由于其在算法软件及其处理能力等原因导致产品在动态性能和初始捕获时间等方面，由于其在像元读出速度和数据处理速度等原因导致产品在数据更新率方面，由于其在光学系统耐辐照能力弱、可靠性设计不足等原因导致产品在工作寿命等核心指标上无法满足上述使用要求，因此需要突破低噪声小型化和高处理能力电路、高像质小型化和高耐辐照非球面光学系统、小型化高消光比遮光罩、小型化高稳定度结构、星图快速处理方法、姿态稳定跟踪方法等关键技术，研究一种高性能的小型长寿命星敏感器。The typical technical indicators of traditional star sensors are: weight 3~5kg, high precision 5~10", dynamic performance 1°/s, data update rate 5~8Hz, initial capture time 10~20s, working life 5~8 years. At the present stage, the mission model requires the technical indicators of the star sensor: weight about 2kg, high precision 3", dynamic performance 3°/s, data update rate 10Hz, initial capture time 1s, working life 15 years, the existing star sensor Due to the low sensitivity of the detector and the large noise of the circuit, the image quality of the large-field and large-aperture optical system is not high, the stray light suppression of the hood is weak, and the structural stability is poor, which leads to the miniaturization of the product. Due to its algorithmic software and its processing power, the product is in terms of dynamic performance and initial capture time. Due to its pixel readout speed and data processing speed, the product is in terms of data update rate. Due to its optical system Due to weak radiation resistance and insufficient reliability design, the product cannot meet the above requirements in terms of core indicators such as working life. Therefore, it is necessary to break through low-noise miniaturization and high-processing capacity circuits, high-quality miniaturization and high radiation resistance. Key technologies such as aspheric optical system, miniaturized high extinction ratio hood, miniaturized high-stability structure, fast processing method of star map, stable attitude tracking method and other key technologies, research a high-performance small and long-life star sensor.
发明内容Contents of the invention
本发明解决的技术问题是：克服现有技术的不足，提供了一种小型长寿命高精度星敏感器，通过采用高透过率高耐辐照光学系统、小型化高消光比遮光罩、高稳定度结构、快速姿态稳定跟踪方法，解决了现有的星敏感器探测灵敏度低、电路噪声大、光学系统像质不高、遮光罩杂光抑制弱的问题。The technical problem solved by the present invention is: to overcome the deficiencies of the prior art, and provide a small-scale long-life high-precision star sensor, by adopting a high-transmittance and high-radiation-resistant optical system, a miniaturized high-extinction ratio hood, a high The stability structure and fast attitude stabilization tracking method solve the problems of low detection sensitivity of the existing star sensor, large circuit noise, low image quality of the optical system, and weak suppression of stray light by the hood.
本发明的技术解决方案是：一种小型长寿命高精度星敏感器，包括遮光罩、光学系统、机械结构、图像传感器电路、控制与数据处理模块、姿态计算模块，其中The technical solution of the present invention is: a small long-life high-precision star sensor, including a light shield, an optical system, a mechanical structure, an image sensor circuit, a control and data processing module, and an attitude calculation module, wherein
遮光罩，遮挡太阳的直射光线，地球、月亮、卫星本体表面及卫星负载设备反射的太阳光线，防止太阳的直射光线，地球、月亮、卫星本体表面及卫星负载设备反射的太阳光线进入光学系统；The shading cover blocks the direct rays of the sun, the sun rays reflected from the surface of the earth, the moon, the satellite body and the satellite load equipment, and prevents the direct rays of the sun, the sun rays reflected from the earth, the moon, the surface of the satellite body and the satellite load equipment from entering the optical system;
光学系统，采集导航恒星能量，并送至图像传感器电路；The optical system collects and navigates star energy and sends it to the image sensor circuit;
图像传感器电路，将导航恒星能量在图像传感器电路光敏面上进行导航恒星星点成像得到导航恒星星图，对导航恒星星图进行光电转换得到数字导航恒星星图，将数字导航恒星星图送至控制与数据处理电路；The image sensor circuit uses the energy of the navigation star on the photosensitive surface of the image sensor circuit to image the star point of the navigation star to obtain a star map of the navigation star, and performs photoelectric conversion to the star map of the navigation star to obtain a digital star map of the navigation star, and sends the digital star map of the navigation star to Control and data processing circuits;
控制与数据处理电路，接收数字导航恒星星图后，计算导航恒星星图背景及导航恒星星图阈值，根据计算得到的导航恒星星图阈值提取导航恒星星图中星点的有效像元，然后对得到的星点的有效像元进行聚类并在聚类过程中进行伪星判别和剔除，得到星点图像，根据星点图像中有效像元计算导航恒星星点的能量重心，然后剔除能量重心过近的两颗导航恒星，然后对剩余的导航恒星星点根据能量进行排序，将导航恒星能量排序后的星点送至姿态计算模块；The control and data processing circuit, after receiving the digital navigation star map, calculates the background of the navigation star map and the threshold value of the navigation star map, and extracts effective pixels of star points in the navigation star map according to the calculated threshold value of the navigation star map, and then Cluster the effective pixels of the obtained star points and perform false star discrimination and elimination during the clustering process to obtain the star point image, calculate the energy center of gravity of the navigation star star point according to the effective pixels in the star point image, and then eliminate the energy The two navigation stars whose centers of gravity are too close, then sort the remaining navigation star points according to energy, and send the star points after the energy sorting of the navigation stars to the attitude calculation module;
姿态计算模块，将导航恒星能量排序后的导航恒星星点与预设的地心惯性坐标系下的导航星表进行匹配识别，进而得到当前星敏感器观测轴在地心惯性坐标系下的矢量指向，最终得到导航恒星姿态数据，并将导航恒星姿态数据输出；所述的导航恒星姿态数据包括星敏感器三个观测轴在地心惯性坐标系下的矢量指向，其中，星敏感器三个观测轴互相垂直；The attitude calculation module matches and identifies the navigation star star points sorted by the energy of the navigation stars with the navigation star catalog in the preset geocentric inertial coordinate system, and then obtains the vector of the current star sensor observation axis in the geocentric inertial coordinate system pointing, and finally obtain the navigation star attitude data, and output the navigation star attitude data; the navigation star attitude data includes the vector pointing of the three observation axes of the star sensor under the earth-centered inertial coordinate system, wherein the three star sensors The observation axes are perpendicular to each other;
机械结构，支撑和固定遮光罩、光学系统、图像传感器电路、控制与数据处理模块、姿态计算模块。Mechanical structure, supporting and fixing the hood, optical system, image sensor circuit, control and data processing module, attitude calculation module.
所述的遮光罩为两段式结构，包括前段、后段，前段、后段内部分别包括三个环形结构的挡光环，前段、后段的直径均匀减小，前段的小直径端与后段的大直径端固定连接，前段小直径端的直径大于后段大直径端的直径，后段的小直径端与机械结构固定连接，挡光环内部表面喷涂吸收率大于0.97的黑漆。The hood is a two-stage structure, including a front section and a rear section. The front section and the rear section respectively include three light-blocking rings of ring structure. The diameters of the front section and the rear section are uniformly reduced. The large diameter end of the front section is fixedly connected, the diameter of the small diameter end of the front section is larger than the diameter of the large diameter end of the rear section, the small diameter end of the rear section is fixedly connected with the mechanical structure, and the inner surface of the halo is sprayed with black paint with an absorption rate greater than 0.97.
所述的光学系统包括5片镜片，第一镜片、第三镜片前表面为凸椭球面，第一镜片后表面、第三镜片后表面、第四镜片的前表面为凸球面，其余镜面为凹球面，第一镜片、第三镜片的材料为JGS1玻璃材料，第二镜片的材料为ZF4、第四镜片材料为ZK9、第五镜片的材料为ZF4；第一镜片、第二镜片、第三镜片、第四镜片、第五镜片依次排列且光轴通过每个镜片的中心，第一镜片前表面设有光阑，入瞳位于第一镜片前表面；导航恒星能量依次通过第一镜片、第二镜片、第三镜片、第四镜片、第五镜片后汇聚至图像传感器电路的光敏面上。The optical system includes 5 lenses, the first lens and the third lens front surface are convex ellipsoids, the first lens rear surface, the third lens rear surface, and the front surface of the fourth lens are convex spherical surfaces, and the remaining mirror surfaces are concave Spherical surface, the material of the first lens and the third lens is JGS1 glass material, the material of the second lens is ZF4, the material of the fourth lens is ZK9, and the material of the fifth lens is ZF4; the material of the first lens, the second lens and the third lens , the fourth lens, and the fifth lens are arranged in sequence and the optical axis passes through the center of each lens. The front surface of the first lens is provided with a diaphragm, and the entrance pupil is located on the front surface of the first lens; The lens, the third lens, the fourth lens and the fifth lens converge on the photosensitive surface of the image sensor circuit.
所述的机械结构包括基座、第一结构支撑柱、第二结构支撑柱、第三结构支撑柱、第四结构支撑柱、上盖板、第一侧板、第二侧板、第三侧板、第四侧板；第一结构支撑柱、第二结构支撑柱、第三结构支撑柱、第四结构支撑柱固定安装在基座上，第一结构支撑柱、第二结构支撑柱、第三结构支撑柱、第四结构支撑柱固定支撑上盖板，第一侧板、第二侧板、第三侧板、第四侧板与基座、上盖板固定连接形成箱体结构；光学系统置于基座中部，图像传感器电路置于光学系统下方，控制与数据处理电路在基座上对称放置，图像传感器电路通过电连接器和控制与数据处理电路连接，遮光罩通固定安装在上盖板上。The mechanical structure includes a base, a first structural support column, a second structural support column, a third structural support column, a fourth structural support column, an upper cover plate, a first side plate, a second side plate, and a third side plate, the fourth side plate; the first structural support column, the second structural support column, the third structural support column, and the fourth structural support column are fixedly installed on the base; the first structural support column, the second structural support column, the second structural support column The three structural support columns and the fourth structural support column fixedly support the upper cover plate, the first side plate, the second side plate, the third side plate, and the fourth side plate are fixedly connected with the base and the upper cover plate to form a box structure; The system is placed in the middle of the base, the image sensor circuit is placed under the optical system, the control and data processing circuits are placed symmetrically on the base, the image sensor circuit is connected with the control and data processing circuit through an electrical connector, and the hood is fixedly installed on the top. cover.
所述的图像传感器电路包括配置电路、时序电路、图像传感器；The image sensor circuit includes a configuration circuit, a sequential circuit, and an image sensor;
配置电路，产生稳定电压送至图像传感器进行供电；时序电路，产生工作时钟并送至图像传感器，驱动像元感光阵列进行光电转换；Configure the circuit to generate a stable voltage and send it to the image sensor for power supply; the sequential circuit generates a working clock and send it to the image sensor to drive the photosensitive array of the pixel for photoelectric conversion;
图像传感器包括像元感光阵列、可编程增益放大器电路、AD转换电路；像元感光阵列接收工作时钟后，将导航恒星能量在图像传感器电路光敏面上进行导航恒星星点成像得到代表导航恒星星图的电压信号，可编程增益放大器电路，对导航恒星星图的电压信号进行电压偏置、电压增益后送至AD转换电路，AD转换电路转换得到数字导航恒星星图，并输出至控制与数据处理电路。The image sensor includes a pixel photosensitive array, a programmable gain amplifier circuit, and an AD conversion circuit; after the pixel photosensitive array receives the working clock, the navigation star energy is imaged on the photosensitive surface of the image sensor circuit to obtain a representative navigation star map The voltage signal, programmable gain amplifier circuit, the voltage signal of the navigation star map is biased and voltage-gained, and then sent to the AD conversion circuit, the AD conversion circuit converts the digital navigation star map, and outputs it to the control and data processing circuit.
所述的控制与数据处理电路包括逻辑控制电路、数字信号处理电路、二次电源电路；The control and data processing circuit includes a logic control circuit, a digital signal processing circuit, and a secondary power supply circuit;
二次电源电路，对逻辑控制电路、数字信号处理电路进行供电；The secondary power supply circuit supplies power to the logic control circuit and digital signal processing circuit;
逻辑控制电路，接收数字导航恒星星图后进行图像预处理，得到各个恒星星点的像素灰度值和位置信息，进而得到导航恒星星图背景及导航恒星星图阈值，然后将各个恒星星点的像素灰度值、位置信息及导航恒星星图背景、导航恒星星图阈送至数字信号处理电路；The logic control circuit, after receiving the digital navigation star map, performs image preprocessing, obtains the pixel gray value and position information of each star point, and then obtains the background of the navigation star map and the threshold value of the navigation star map, and then converts each star point The pixel gray value, position information, background of the navigation star map, and threshold of the navigation star map are sent to the digital signal processing circuit;
数字信号处理电路，根据导航恒星星图阈值提取导航恒星星图中星点的有效像元，然后对得到的星点的有效像元进行聚类并在聚类过程中进行伪星判别和剔除，得到星点图像，根据星点图像中有效像元计算导航恒星星点的能量重心，然后剔除能量重心过近的两颗导航恒星，对剩余的导航恒星星点根据能量进行排序，将导航恒星能量排序后的星点送至姿态计算模块。The digital signal processing circuit extracts effective pixels of star points in the navigation star map according to the threshold of the navigation star map, then clusters the effective pixels of the obtained star points and performs false star discrimination and elimination in the clustering process, Get the star point image, calculate the energy center of gravity of the star point of the navigation star according to the effective pixels in the star point image, and then remove the two navigation stars whose energy center of gravity is too close, sort the remaining star points of the navigation star according to the energy, and convert the energy of the navigation star The sorted star points are sent to the attitude calculation module.
所述的姿态计算模块中将导航恒星能量排序后的导航恒星星点与预设的地心惯性坐标系下的导航星表进行匹配识别的方法包括如下步骤：The method for matching and identifying the navigation star star points after the navigation star energy sorting with the navigation star catalog under the preset earth-centered inertial coordinate system in the described attitude calculation module includes the following steps:
(1)对预设的地心惯性坐标系下的导航星表中导航恒星对角距进行星等、数量筛选，得到N个星等不大于7等星的导航恒星及对应的导航恒星对角距，其中，N为[5-20]；(1) Screen the magnitude and number of navigation stars in the navigation star catalog under the preset geocentric inertial coordinate system, and obtain N navigation stars whose magnitude is not greater than 7th magnitude and the corresponding navigation star diagonals Distance, wherein, N is [5-20];
(2)对能量排序后的导航恒星星点利用三角形选择方法构建观测星三角形，然后根据步骤(1)得到的导航恒星对角距对观测星三角形进行三角形匹配识别，若匹配识别的结果唯一，则计算星敏感器三个观测轴在地心惯性坐标系下的矢量指向并进行投影验证，将匹配识别结果唯一的观测星投影在星敏感器观测像面，当星敏感器观测像面上导航恒星与观测星投影之间的夹角在[0-120″]之间时，投影验证通过，将星敏感器三个观测轴在地心惯性坐标系下的矢量指向作为导航恒星姿态数据并输出，若匹配识别的结果不唯一，则对能量排序后的导航恒星星点进行四面体识别，当四面体识别结果唯一时，将匹配识别结果唯一的观测星投影在星敏感器观测像面，如果星敏感器观测像面上导航恒星与观测星投影之间的夹角在[0-120″]之间，则将星敏感器三个观测轴在地心惯性坐标系下的矢量指向作为导航恒星姿态数据并输出。(2) Use the triangle selection method to construct the observation star triangle for the navigation star points after energy sorting, and then carry out triangle matching and identification on the observation star triangle according to the navigation star diagonal distance obtained in step (1). If the matching identification result is unique, Then calculate the vector orientation of the three observation axes of the star sensor in the earth-centered inertial coordinate system and carry out projection verification, and project the observation star with the only matching identification result on the observation image surface of the star sensor. When the star sensor observation image surface navigates When the angle between the star and the observation star projection is between [0-120″], the projection verification is passed, and the vector pointing of the three observation axes of the star sensor in the earth-centered inertial coordinate system is used as the navigation star attitude data and output , if the result of matching and recognition is not unique, carry out tetrahedron recognition on the energy sorted navigation star points. If the angle between the navigation star and the projection of the observation star on the observation image plane of the star sensor is between [0-120″], then the vector pointing of the three observation axes of the star sensor in the earth-centered inertial coordinate system is used as the navigation star Attitude data and output.
所述的导航恒星姿态数据使用跟踪列表结构进行存储记录，以得到星敏感器对导航恒星的跟踪识别情况。The attitude data of the navigation star is stored and recorded using a tracking list structure, so as to obtain the tracking and identification of the navigation star by the star sensor.
所述的遮光罩内倾斜角度为30°。The inclination angle of the shading cover is 30°.
本发明与现有技术相比的优点在于：The advantage of the present invention compared with prior art is:
(1)本发明星敏感器与现有技术相比，通过采用高透过率高耐辐照光学系统、小型化高消光比遮光罩、高稳定度结构、快速姿态稳定跟踪方法，提高了本发明星敏感器的测量精度、动态性能，具有小型化和长寿命的优点；(1) Compared with the prior art, the star sensor of the present invention improves the star sensor by adopting high transmittance and high radiation resistance optical system, miniaturization and high extinction ratio shading cover, high stability structure, and fast attitude stable tracking method. The measurement accuracy and dynamic performance of the invented star sensor have the advantages of miniaturization and long life;
(2)本发明星敏感器与现有技术相比，采用大视场小型化耐辐照非球面光学系统，通过将相同参数的光学系统光学玻璃片减少为5片，提高了星敏感器的高像质、小型化和高耐辐照。(2) Compared with the prior art, the star sensor of the present invention adopts the miniaturization and radiation-resistant aspheric optical system of large field of view, and reduces the optical glass sheets of the optical system with the same parameters to 5 pieces, which improves the star sensor performance. High image quality, miniaturization and high radiation resistance.
附图说明Description of drawings
图1为本发明一种小型长寿命高精度星敏感器工作流程图；Fig. 1 is a kind of small-sized long-life high-precision star sensor working flow chart of the present invention;
图2为本发明星敏感器中遮光罩结构示意图；Fig. 2 is a schematic diagram of the light shield structure in the star sensor of the present invention;
图3为本发明星敏感器中光学系统光路结构图；Fig. 3 is the structural diagram of the light path of the optical system in the star sensor of the present invention;
图4为本发明星敏感器中机械结构示意图；Fig. 4 is a schematic diagram of the mechanical structure in the star sensor of the present invention;
图5为本发明星敏感器中能量排序后的导航恒星星点与预设的地心惯性坐标系下的导航星表进行匹配识别的方法流程图。Fig. 5 is a flowchart of a method for matching and identifying navigation star points after energy sorting in the star sensor of the present invention and a navigation star catalog in a preset geocentric inertial coordinate system.
具体实施方式detailed description
目前相关任务型号对星敏感器提出了小型化、长寿命和高可靠性的要求。现有工程化星敏感器产品都无法满足上述型号对星敏感器的指标要求，同时小型化、长寿命、高数据更新速率也是星敏感器发展的必然方向，因此亟需针对上述需求开发相应的星敏感器工程化产品，其中，相关任务型号需要的小型长寿命星敏感器的技术特点包括：高测量精度3＂(3σ)、高动态性能3°/s、高数据更新率10Hz、短初始捕获时间1s、高太阳光抑制角26°、小型化(整机重量含遮光罩2.1kg)、长寿命15年等。At present, relevant task models have put forward requirements for miniaturization, long life and high reliability of star sensors. None of the existing engineered star sensor products can meet the requirements of the above models for star sensors. At the same time, miniaturization, long life, and high data update rate are also the inevitable direction of star sensor development. Therefore, it is urgent to develop corresponding Star sensor engineering products, among them, the technical characteristics of the small long-life star sensor required by the relevant mission models include: high measurement accuracy 3" (3σ), high dynamic performance 3°/s, high data update rate 10Hz, short initial The capture time is 1s, the high sunlight suppression angle is 26°, the miniaturization (the weight of the whole machine including the hood is 2.1kg), the long life of 15 years, etc.
传统的星敏感器一般基于CCD图像传感器，但是随着微电子技术的发展，出现了一种基于CMOS工艺的APS图像传感器，其具有小型化、低功耗、高耐辐照、高集成度、接口简单等优点，是星敏感器的重要发展方向。目前星敏感器主要研究机构都在积极研究APS图像传感器的应用，现阶段小型化、微型化、纳型化星敏感器均基于APS图像传感器。Traditional star sensors are generally based on CCD image sensors, but with the development of microelectronics technology, an APS image sensor based on CMOS technology has emerged, which has the advantages of miniaturization, low power consumption, high radiation resistance, high integration, The advantage of simple interface is an important development direction of star sensors. At present, the main research institutes of star sensors are actively studying the application of APS image sensors. At this stage, miniaturized, miniaturized, and nano-sized star sensors are all based on APS image sensors.
本发明提出一种小型长寿命高精度星敏感器，设计研制了高灵敏度、低噪声APS图像传感器和SoC处理器，设计了低噪声、小型化、高处理能力电路，实现了高测量精度、高数据更新率，设计大视场非球面光学系统设计方法和研制高耐辐照光学玻璃材料，实现了光学系统的高像质、小型化和高耐辐照，设计了一种小型化高消光比遮光罩和一种小型化高稳定度结构，实现了遮光罩的小太阳光抑制角、小型化和轻量化，实现了整机结构的小型化和良好的热稳定性，设计了一种星图快速处理方法和一种姿态稳定跟踪方法，实现了星敏感器短初始捕获时间。The invention proposes a small, long-life and high-precision star sensor, designs and develops a high-sensitivity, low-noise APS image sensor and SoC processor, designs a low-noise, miniaturized, and high-processing circuit, and realizes high measurement accuracy, high Data update rate, design of large field of view aspheric optical system design method and development of high radiation resistance optical glass material, realized high image quality, miniaturization and high radiation resistance of the optical system, designed a miniaturized high extinction ratio The sunshade and a miniaturized high-stability structure realize the small sunlight suppression angle, miniaturization and light weight of the sunshade, realize the miniaturization of the whole machine structure and good thermal stability, and design a star map A fast processing method and an attitude-stabilized tracking method achieve a short initial acquisition time for the star sensor.
本发明星敏感器工作原理包括：星敏感器中的光学系统将恒星成像于图像传感器(如CCD、APS等)的光敏面上，由图像传感器完成光电转换，输出模拟信号经AD转换后送数据处理电路，对恒星位置进行提取，可确定视场中的恒星在星敏感器本体坐标系下的坐标和指向，与导航星表进行比对，完成星图识别，最终确定星敏感器光轴在惯性坐标系下的指向。卫星或航天器通过星敏感器的安装矩阵确定卫星或航天器本身在惯性坐标系下的三轴姿态，并通过星敏感器通讯接口将三轴姿态传送至姿轨控计算机，下面结合附图对本发明星敏感器的具体实施方式进行进一步的详细描述。The working principle of the star sensor of the present invention includes: the optical system in the star sensor images the star on the photosensitive surface of the image sensor (such as CCD, APS, etc.), completes the photoelectric conversion by the image sensor, and sends the data after the analog signal is converted by AD The processing circuit extracts the position of the stars, and can determine the coordinates and orientation of the stars in the field of view in the coordinate system of the star sensor body, compare them with the navigation star catalog, complete the star map identification, and finally determine that the optical axis of the star sensor is at Orientation in inertial coordinate system. The satellite or spacecraft determines the three-axis attitude of the satellite or spacecraft itself in the inertial coordinate system through the installation matrix of the star sensor, and transmits the three-axis attitude to the attitude and orbit control computer through the communication interface of the star sensor. The specific embodiment of the inventive star sensor is further described in detail.
星敏感器包括硬件和软件两部分组成，其中，硬件主要由遮光罩、光学系统、机械结构、图像传感器电路、控制与数据处理电路等构成，软件由系统软件、应用软件和星表软件三个部分组成，如图1所示为本发明一种小型长寿命高精度星敏感器工作流程图。The star sensor consists of hardware and software. Among them, the hardware is mainly composed of a light shield, optical system, mechanical structure, image sensor circuit, control and data processing circuit, etc., and the software consists of three parts: system software, application software and star catalog software. Partial composition, as shown in Figure 1, is a working flow chart of a small-sized long-life high-precision star sensor of the present invention.
遮光罩遮挡直接来自太阳的光线进入光学系统，遮挡地球、月亮以及卫星本体表面和部件反射的太阳光线。遮光罩结构形式的确定与杂散光的衰减需求、星敏感器视场角、遮光罩口径和长度、内表面涂层吸收特性、杂散光光源的种类和分布、杂散光强度等因素相关。根据对遮光罩杂光抑制能力的分析以及外形尺寸的限制，小型长寿命星敏感器采用吸收型一级挡光环式遮光罩。遮光罩的消杂光能力与表面吸收系数有直接关系，同时合理的设计遮光罩内部结构也有利于提高其消杂光能力。小型长寿命星敏感器遮光罩内部表面喷涂进口高吸收率黑漆，黑漆吸收率大于0.97，在真空紫外辐照、抗原子氧及湿热老化具有较好的稳定性，有多次上天飞行经历，小型长寿命星敏感器遮光罩如图2所示，包括前段11、后段12，前段11、后段12内部分别包括三个环形结构的挡光环，前段11、后段12的直径均匀减小，前段11的小直径端与后段12的大直径端固定连接，前段11小直径端的直径大于后段12大直径端的直径，后段12的小直径端与机械结构固定连接。The sunshade blocks the light directly from the sun from entering the optical system, and blocks the sun's light reflected from the surface and components of the earth, moon, and satellite body. The determination of the structure of the hood is related to the attenuation requirements of stray light, the field of view of the star sensor, the diameter and length of the hood, the absorption characteristics of the inner surface coating, the type and distribution of stray light sources, and the intensity of stray light. According to the analysis of the stray light suppression ability of the hood and the limitation of the external size, the small and long-life star sensor adopts the absorbing first-stage halo-type hood. The ability to eliminate stray light of the hood is directly related to the surface absorption coefficient, and a reasonable design of the internal structure of the hood is also conducive to improving its ability to eliminate stray light. The internal surface of the small long-life star sensor hood is sprayed with imported high-absorption black paint. The black paint has an absorption rate greater than 0.97. It has good stability in vacuum ultraviolet radiation, anti-atomic oxygen and humid heat aging. It has many flight experiences , the small-sized long-life star sensor hood as shown in Figure 2, comprises front section 11, back section 12, and front section 11, back section 12 interior respectively comprises the light-blocking ring of three annular structures, and the diameter of front section 11, back section 12 reduces evenly Small, the small diameter end of the front section 11 is fixedly connected with the large diameter end of the rear section 12, the diameter of the small diameter end of the front section 11 is greater than the diameter of the large diameter end of the rear section 12, and the small diameter end of the rear section 12 is fixedly connected with the mechanical structure.
光学系统将恒星能量汇聚透射成像于图像传感器光敏面上，保证星敏感器视场角、焦距、光谱范围、相对孔径等性能指标，保证倍率色差、色畸变、畸变、弥散斑等成像质量要求。小型长寿命星敏感器光学系统的特点为长寿命、中等视场、大相对孔径、弥散斑尺寸严格、镜头质量较轻等，因此设计为非球面光阑前置型，包括5片镜片，第一镜片、第三镜片前表面为凸椭球面，第一镜片后表面、第三镜片后表面、第四镜片的前表面为凸球面，其余镜面为凹球面，第一镜片、第三镜片的材料为JGS1玻璃材料，第二镜片的材料为ZF4、第四镜片材料为ZK9、第五镜片的材料为ZF4；第一镜片、第二镜片、第三镜片、第四镜片、第五镜片依次排列且光轴通过每个镜片的中心，第一镜片前表面设有光阑，入瞳位于第一镜片前表面；导航恒星能量依次通过第一镜片、第二镜片、第三镜片、第四镜片、第五镜片后汇聚至图像传感器电路的光敏面上。GS1材料性质稳定，具有抗辐照、抗腐蚀、热膨胀系数较小、密度较低的优点，有利于非球面的加工和提高系统空间环境的适应性。其中，小型长寿命星敏感器光学系统光路结构图如图3所示。The optical system gathers and transmits the star energy and images it on the photosensitive surface of the image sensor to ensure performance indicators such as the field of view, focal length, spectral range, and relative aperture of the star sensor, and to ensure imaging quality requirements such as chromatic aberration of magnification, color distortion, distortion, and diffuse spots. The optical system of the small long-life star sensor is characterized by long life, medium field of view, large relative aperture, strict size of the diffuse spot, light lens quality, etc., so it is designed as an aspherical diaphragm front type, including 5 lenses, the first The front surfaces of the first lens and the third lens are convex ellipsoidal surfaces, the rear surfaces of the first lens, the third lens rear surface, and the fourth lens are convex spherical surfaces, and the remaining mirror surfaces are concave spherical surfaces. The materials of the first lens and the third lens It is JGS1 glass material, the material of the second lens is ZF4, the material of the fourth lens is ZK9, and the material of the fifth lens is ZF4; the first lens, the second lens, the third lens, the fourth lens, and the fifth lens are arranged in sequence and The optical axis passes through the center of each lens, the front surface of the first lens is provided with a diaphragm, and the entrance pupil is located on the front surface of the first lens; the navigation star energy passes through the first lens, the second lens, the third lens, the fourth lens, and the fourth lens in turn. The five mirrors converge on the photosensitive surface of the image sensor circuit. GS1 material is stable in properties, has the advantages of radiation resistance, corrosion resistance, small thermal expansion coefficient, and low density, which is beneficial to the processing of aspheric surfaces and improving the adaptability of the system space environment. Among them, the optical path structure diagram of the optical system of the small long-life star sensor is shown in Figure 3.
机械结构支撑和固定遮光罩、光学系统和电路板，同时承担电子元器件部分抗辐照屏蔽作用。小型长寿命星敏感器整机结构的主要技术特点为：重量2.1kg，整机结构设计了一体化的“框架组合环绕式”结构型式，该结构以基座作为核心，基座的中心装配有光学成像组件，基座通过4个结构支撑柱与上盖相连构成一个主承力结构组件，4个侧板同时装配在基座和上盖上构成了一个封闭的整体结构，电路板组件则直接装在侧板上或直接装在结构支撑柱上，遮光罩装配上在上盖板上。小型长寿命星敏感器机械结构图如图4所示，基座1、第一结构支撑柱2、第二结构支撑柱3、第三结构支撑柱4、第四结构支撑柱5、上盖板6、第一侧板7、第二侧板8、第三侧板9、第四侧板10；第一结构支撑柱2、第二结构支撑柱3、第三结构支撑柱4、第四结构支撑柱5固定安装在基座1上，第一结构支撑柱2、第二结构支撑柱3、第三结构支撑柱4、第四结构支撑柱5固定支撑上盖板6，第一侧板7、第二侧板8、第三侧板9、第四侧板10与基座1、上盖板6固定连接形成箱体结构；光学系统置于基座1中部，图像传感器电路置于光学系统下方，控制与数据处理电路在基座1上对称放置，图像传感器电路通过电连接器和控制与数据处理电路连接，遮光罩通固定安装在上盖板6上，该结构型式紧凑，易于实现产品小型化；光学系统与APS器件之间的连接的结构材料均采用钛合金，使光学成像组件具有良好的热稳定性。The mechanical structure supports and fixes the hood, optical system and circuit board, and at the same time assumes part of the anti-radiation shielding effect of electronic components. The main technical features of the whole structure of the small long-life star sensor are as follows: the weight is 2.1kg. Optical imaging components, the base is connected to the upper cover through four structural support columns to form a main load-bearing structural component, the four side plates are assembled on the base and the upper cover at the same time to form a closed overall structure, and the circuit board component is directly Installed on the side panel or directly on the structural support column, the hood is assembled on the upper cover. The mechanical structure diagram of the small long-life star sensor is shown in Figure 4, the base 1, the first structural support column 2, the second structural support column 3, the third structural support column 4, the fourth structural support column 5, and the upper cover 6. The first side panel 7, the second side panel 8, the third side panel 9, the fourth side panel 10; the first structure support column 2, the second structure support column 3, the third structure support column 4, the fourth structure The support column 5 is fixedly installed on the base 1, the first structural support column 2, the second structural support column 3, the third structural support column 4, and the fourth structural support column 5 fixedly support the upper cover plate 6, and the first side plate 7 , the second side plate 8, the third side plate 9, the fourth side plate 10 are fixedly connected with the base 1 and the upper cover plate 6 to form a box structure; the optical system is placed in the middle of the base 1, and the image sensor circuit is placed in the optical system Below, the control and data processing circuits are symmetrically placed on the base 1, the image sensor circuit is connected with the control and data processing circuit through an electrical connector, and the shading cover is fixedly installed on the upper cover plate 6. This structure is compact and easy to implement. Miniaturization; the structural material of the connection between the optical system and the APS device is made of titanium alloy, which makes the optical imaging component have good thermal stability.
图像传感器电路(包括配置电路、时序电路、图像传感器)，完成恒星光能量的光电转换，并生成数字星图，图像传感器电路需保证较高的信噪比和较小的暗电流。配置电路，产生稳定电压送至图像传感器进行供电；时序电路，产生工作时钟并送至图像传感器，驱动像元感光阵列进行光电转换；图像传感器包括像元感光阵列、可编程增益放大器电路、AD转换电路；像元感光阵列接收工作时钟后，将导航恒星能量在图像传感器电路光敏面上进行导航恒星星点成像得到代表导航恒星星图的电压信号，可编程增益放大器电路，对导航恒星星图的电压信号进行电压偏置、电压增益后送至AD转换电路，AD转换电路转换得到数字导航恒星星图，并输出至控制与数据处理电路。其中，图像传感器采用基于CMOS工艺的定制APS图像传感器COMPASS，该图像传感器为抗辐照工艺4T像素结构，相比目前常用的3T像素结构，可降低复位噪声、读出噪声和固定模式噪声。COMPASS片上集成12位高速ADC，可进一步提高星敏感器单星定位精度。COMPASS图像传感器QE×FF为50％，读出噪声优于25e-，动态范围72dB，抗辐照能力100kRad。图像传感器的时序逻辑芯片采用自研星图处理专用集成电路(ASIC)，基于图像传感器和ASIC，设计了低噪声视频电路，小型长寿命高精度星敏感器视频电路总噪声60e-。The image sensor circuit (including configuration circuit, timing circuit, and image sensor) completes the photoelectric conversion of star light energy and generates a digital star map. The image sensor circuit needs to ensure a high signal-to-noise ratio and a small dark current. Configure the circuit to generate a stable voltage and send it to the image sensor for power supply; the sequential circuit generates the working clock and sends it to the image sensor to drive the photosensitive array of the pixel for photoelectric conversion; the image sensor includes a photosensitive array of the pixel, a programmable gain amplifier circuit, AD conversion circuit; after the pixel photosensitive array receives the working clock, the navigation star energy is imaged on the photosensitive surface of the image sensor circuit to obtain the voltage signal representing the navigation star map, and the programmable gain amplifier circuit is used for the navigation star map. After voltage biasing and voltage gain, the voltage signal is sent to the AD conversion circuit, and the AD conversion circuit converts to obtain a digital navigation star map, and outputs it to the control and data processing circuit. Among them, the image sensor adopts the custom APS image sensor COMPASS based on the CMOS process. The image sensor has a radiation-resistant 4T pixel structure. Compared with the currently commonly used 3T pixel structure, it can reduce reset noise, readout noise and fixed pattern noise. COMPASS integrates a 12-bit high-speed ADC on-chip, which can further improve the single-satellite positioning accuracy of the star sensor. The QE×FF of the COMPASS image sensor is 50%, the readout noise is better than 25e-, the dynamic range is 72dB, and the anti-irradiation ability is 100kRad. The sequential logic chip of the image sensor adopts a self-developed star image processing application-specific integrated circuit (ASIC). Based on the image sensor and ASIC, a low-noise video circuit is designed. The total noise of the video circuit of the small, long-life and high-precision star sensor is 60e-.
控制与数据处理电路包括逻辑控制电路、数字信号处理电路、二次电源电路，完成星图预处理、星图提取、星图匹配、姿态计算，内含二次电源电路可根据一次电源母线产生星敏感器内部所需的各种二次电源电压；逻辑控制电路，接收数字导航恒星星图后进行图像预处理，得到各个恒星星点的像素灰度值和位置信息，进而得到导航恒星星图背景及导航恒星星图阈值，然后将各个恒星星点的像素灰度值、位置信息及导航恒星星图背景、导航恒星星图阈值送至数字信号处理电路；数字信号处理电路，根据导航恒星星图阈值提取导航恒星星图中星点的有效像元，然后对得到的星点的有效像元进行聚类并在聚类过程中进行伪星判别和剔除，得到星点图像，根据星点图像中有效像元计算导航恒星星点的能量重心，然后剔除能量重心过近的两颗导航恒星，对剩余的导航恒星星点根据能量进行排序，将导航恒星能量排序后的星点送至姿态计算模块。The control and data processing circuit includes a logic control circuit, a digital signal processing circuit, and a secondary power supply circuit to complete star map preprocessing, star map extraction, star map matching, and attitude calculation. The various secondary power supply voltages required inside the sensor; the logic control circuit, after receiving the digital navigation star map, performs image preprocessing to obtain the pixel gray value and position information of each star point, and then obtain the background of the navigation star map and the navigation star map threshold, and then send the pixel gray value, position information, navigation star map background, and navigation star map threshold of each star point to the digital signal processing circuit; the digital signal processing circuit, according to the navigation star map Threshold extracts the effective pixels of the star point in the navigation star map, and then clusters the effective pixels of the obtained star point and performs false star discrimination and elimination in the clustering process to obtain the star point image, according to the star point image The effective pixel calculates the energy center of gravity of the star points of the navigation stars, and then removes the two navigation stars whose energy centers of gravity are too close, sorts the remaining star points of the navigation stars according to the energy, and sends the star points after the energy sorting of the navigation stars to the attitude calculation module .
其中，星图预处理由逻辑控制电路ASIC完成，其输入为图像传感器电路输出的数字星图，输出为预处理后的各个恒星星点的像素灰度值、位置信息及导航恒星星图背景、导航恒星星图阈值，该逻辑控制ASIC电路基于0.18um工艺进行设计，电路规模为百万门，采用抗辐射加固设计，工作电压I/O为3.3V、内核1.8V，单粒子SEL为75Mev.cm2/mg，抗辐射总剂量100kRad，逻辑控制ASIC电路主要设计有CPU读写、复位、时钟分频、APS参数设置、APS曝光控制、图像预处理、图像输出并串处理、图像输入串并处理、外同步信号曝光控制等功能。Among them, the star map preprocessing is completed by the logic control circuit ASIC, the input is the digital star map output by the image sensor circuit, and the output is the pixel gray value, position information and navigation star map background of each star point after preprocessing, Navigation star map threshold, the logic control ASIC circuit is designed based on 0.18um process, the circuit scale is one million gates, it adopts radiation-resistant hardening design, the working voltage I/O is 3.3V, the core is 1.8V, and the single-particle SEL is 75Mev. cm 2 /mg, the total dose of anti-radiation is 100kRad, and the logic control ASIC circuit is mainly designed with CPU read and write, reset, clock frequency division, APS parameter setting, APS exposure control, image preprocessing, image output parallel processing, image input serial parallel Processing, external synchronization signal exposure control and other functions.
数字信号处理电路包括处理器、存储器及接口电路，其中，处理器SoC2008的最高工作频率100MHz，数据处理能力86MIPS和25MFLOPS，数据总线为32位数据+8位校验，可完全三模冗余(TMR)、数据总线检错纠错(EDAC)、多种总线奇偶校验(PAR)能力，寻址空间4G字节(28位地址线)，抗辐射总剂量300kRad，数字信号处理电路的输入为逻辑控制电路输出各个恒星星点的像素灰度值、位置信息及导航恒星星图背景、导航恒星星图阈值，输出为星敏感器姿态信息。The digital signal processing circuit includes a processor, a memory and an interface circuit. Among them, the highest operating frequency of the processor SoC2008 is 100MHz, and the data processing capacity is 86MIPS and 25MFLOPS. TMR), data bus error detection and correction (EDAC), multiple bus parity check (PAR) capabilities, addressing space 4G bytes (28-bit address line), total radiation dose 300kRad, the input of the digital signal processing circuit is The logic control circuit outputs the pixel gray value and position information of each star point, the background of the navigation star map, the threshold value of the navigation star map, and the output is the attitude information of the star sensor.
如图1所示，本发明星敏感器的具体工作流程包括As shown in Figure 1, the specific work flow of star sensor of the present invention comprises
(1)光学系统对导航恒星能量进行采集汇聚，将星点成像于APS图像传感器光敏面上；(1) The optical system collects and converges the energy of the navigation stars, and images the star points on the photosensitive surface of the APS image sensor;
(2)APS图像传感器对恒星能量进行光电转换，生成数字星图；(2) The APS image sensor performs photoelectric conversion of star energy to generate a digital star map;
(3)数字处理电路对星图预处理，完成恒星星点位置提取；其中，星图预处理内容包括星图背景计算、星图阈值计算、星点有效像元提取、观测星聚类提取，伪星判别和剔除、星点能量重心计算、过近观测星剔除、观测星能量排序等步骤。(3) The digital processing circuit preprocesses the star map to complete the extraction of star point positions; wherein, the star map preprocessing content includes star map background calculation, star map threshold calculation, star point effective pixel extraction, and observation star cluster extraction, Discrimination and elimination of false stars, calculation of center of gravity of star point energy, elimination of too close observed stars, energy ranking of observed stars, etc.
(4)采用全天球捕获识别、局部天区识别、或窗口跟踪模式识别等算法中的一种，将星图中恒星与导航星表进行匹配识别处理，识别出所摄星图对应的天球位置，从而确定星敏感器观测轴在惯性空间的矢量方向；(由星图中恒星位置计算星敏感器光轴指向方法，参见参考书籍：卫星轨道姿态动力学与控制，章仁为编著，北京航空航天大学出版社，1998年8月第1版，2005年1月第2次印刷。参考书籍中“卫星姿态的确定”章节)。(4) Use one of the algorithms of full celestial capture recognition, partial sky area recognition, or window tracking pattern recognition to match and identify the stars in the star map and the navigation star catalog, and identify the celestial position corresponding to the captured star map , so as to determine the vector direction of the observation axis of the star sensor in the inertial space; (the method of calculating the optical axis pointing of the star sensor from the star position in the star map, refer to the reference book: Dynamics and Control of Satellite Orbital Attitude, edited by Zhang Renwei, Beijing Aerospace University Press, first edition in August 1998, second printing in January 2005. Reference book "Determination of Satellite Attitude" chapter).
(5)星敏感器通过特定通迅接口与姿轨控计算机进行数据交换，接收控制计算机发送的控制命令和姿态数据(星敏感器工作在局部天区模式下，需要控制计算机发送初始姿态信息)，并将姿态数据输出。(5) The star sensor exchanges data with the attitude control computer through a specific communication interface, and receives the control commands and attitude data sent by the control computer (the star sensor works in the local sky area mode, and the control computer needs to send initial attitude information) , and output the pose data.
通过上述过程能够得到具有高精度、高动态、小型化和长寿命等总体特征的本发明一种小型长寿命高精度星敏感器，主要性能参数包括：星敏感器测量精度为3＂(3σ)、动态性能为3°/s、数据更新率为10Hz、整机重量(含遮光罩)为2.1kg、初始捕获时间1s、太阳光抑制角26°、设计寿命为15年。Through the above process, a small-sized, long-life and high-precision star sensor of the present invention can be obtained with the overall characteristics of high precision, high dynamics, miniaturization and long life. The main performance parameters include: the measurement accuracy of the star sensor is 3" (3σ) , The dynamic performance is 3°/s, the data update rate is 10Hz, the weight of the whole machine (including the hood) is 2.1kg, the initial capture time is 1s, the sunlight suppression angle is 26°, and the design life is 15 years.
本发明星敏感器首次设计并采用了非球面光学系统，将光学系统由8片光学玻璃减小为5片，并实现了光学系统的高像质和小型化；本发明星敏感器设计并选用有抗辐照指标的光学玻璃材料，保证该光学系统在整个工作谱段内具有较高的透过率，寿命末期光学系统透过率满足15年GEO轨道辐照剂量要求；本发明星敏感器中遮光罩采用一级遮光罩结构型式，优化了遮光罩内部挡光板个数(6片挡光环)，调整挡光板在遮光罩内倾斜角度(30°)，使星敏感器在遮光罩外形尺寸缩小的情况下实现杂光抑制能力的大幅提升；本发明机械结构采用一体化的“框架组合环绕式”结构型式，该结构型式紧凑，易于实现产品小型化，光学系统与APS器件之间的连接的结构材料均采用钛合金TC4，使光学成像组件具有良好的热稳定性。The star sensor of the present invention designs and adopts an aspheric optical system for the first time, reduces the optical system from 8 pieces of optical glass to 5 pieces, and realizes the high image quality and miniaturization of the optical system; the star sensor of the present invention is designed and selected The optical glass material with anti-radiation index ensures that the optical system has a high transmittance in the entire working spectrum, and the transmittance of the optical system at the end of the service life meets the radiation dose requirements of the 15-year GEO orbit; the star sensor of the present invention The middle hood adopts a first-class hood structure, which optimizes the number of light baffles inside the hood (6 shading rings), and adjusts the inclination angle (30°) of the light baffles inside the hood to make the star sensor fit within the overall size of the hood. The ability to suppress stray light is greatly improved in the case of shrinkage; the mechanical structure of the present invention adopts an integrated "frame combination surround" structure type, which is compact and easy to realize product miniaturization. The connection between the optical system and the APS device All structural materials are made of titanium alloy TC4, which makes the optical imaging components have good thermal stability.
如图5所示为姿态计算模块中将导航恒星能量排序后的导航恒星星点与预设的地心惯性坐标系下的导航星表进行匹配识别的方法流程图，包括如下步骤：As shown in Figure 5, it is a flow chart of a method for matching and identifying the navigation star star points after the navigation star energy sorting with the navigation star catalog under the preset earth-centered inertial coordinate system in the attitude calculation module, including the following steps:
(1)对预设的地心惯性坐标系下的导航星表中导航恒星对角距进行星等、数量筛选，得到N个星等不大于7等星的导航恒星及对应的导航恒星对角距，其中，N为[5-20]；(1) Screen the magnitude and number of navigation stars in the navigation star catalog under the preset geocentric inertial coordinate system, and obtain N navigation stars whose magnitude is not greater than 7th magnitude and the corresponding navigation star diagonals Distance, wherein, N is [5-20];
(2)对能量排序后的导航恒星星点利用三角形选择方法构建观测星三角形，然后根据步骤(1)得到的导航恒星对角距对观测星三角形进行三角形匹配识别，若匹配识别的结果唯一，则计算星敏感器三个观测轴在地心惯性坐标系下的矢量指向并进行投影验证，将匹配识别结果唯一的观测星投影在星敏感器观测像面，当星敏感器观测像面上导航恒星与观测星投影之间的夹角在[0-120″]之间时，投影验证通过，将星敏感器三个观测轴在地心惯性坐标系下的矢量指向作为导航恒星姿态数据并输出，若匹配识别的结果不唯一，则对能量排序后的导航恒星星点进行四面体识别，当四面体识别结果唯一时，将匹配识别结果唯一的观测星投影在星敏感器观测像面，如果星敏感器观测像面上导航恒星与观测星投影之间的夹角在[0-120″]之间，则将星敏感器三个观测轴在地心惯性坐标系下的矢量指向作为导航恒星姿态数据并输出(2) Use the triangle selection method to construct the observation star triangle for the navigation star points after energy sorting, and then carry out triangle matching and identification on the observation star triangle according to the navigation star diagonal distance obtained in step (1). If the matching identification result is unique, Then calculate the vector orientation of the three observation axes of the star sensor in the earth-centered inertial coordinate system and carry out projection verification, and project the observation star with the only matching identification result on the observation image surface of the star sensor. When the star sensor observation image surface navigates When the angle between the star and the observation star projection is between [0-120″], the projection verification is passed, and the vector pointing of the three observation axes of the star sensor in the earth-centered inertial coordinate system is used as the navigation star attitude data and output , if the result of matching and recognition is not unique, carry out tetrahedron recognition on the energy sorted navigation star points. If the angle between the navigation star and the projection of the observation star on the observation image plane of the star sensor is between [0-120″], then the vector pointing of the three observation axes of the star sensor in the earth-centered inertial coordinate system is used as the navigation star Attitude data and output
另外，本发明星敏感器通过建立跟踪列表结构，记录恒星的跟踪识别情况，筛选出稳定跟踪的星点并只采用可被星敏感器稳定跟踪的星对进行姿态解算，消除不能稳定识别星对对应输出姿态的影响，提高星敏感器输出姿态的稳定度。In addition, the star sensor of the present invention records the tracking and identification of stars by establishing a tracking list structure, screens out stable tracking star points, and only uses star pairs that can be stably tracked by the star sensor to perform attitude calculations, eliminating the need for stars that cannot be stably identified. The impact on the corresponding output attitude improves the stability of the star sensor output attitude.
本发明说明书中未作详细描述的内容属本领域技术人员的公知技术。The content that is not described in detail in the description of the present invention belongs to the well-known technology of those skilled in the art.
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