大口径长焦距空间相机热门机构方案研究

相机热门是大口径高分辨率空间相机的关键部件。文章概要介绍了空间相机热门机构的组成、工作原理及设计要点。     

飞行环境污染对航天器的影响

论述了卫星等航天器的飞行环境污染源及其影响特性，指出，从流体力学观点，在高真空低温环境状态下，喷气羽流污染影响范围有限，对航天器的空间交会或液体空间排放，只要采取相应的措施，就能够避免其对航天器的污染或损害。     

倾斜CCD光敏面以减小扩展像斑的分析

经理论推导，给出了倾斜ＣＣＤ光敏面以减小扩展像斑，从而减小激光三角法测量误差的理论根据，同时结合计算机模拟曲线，说明了它的缺点是限制了测量范围。     

基于FPGA的星敏感器探测器制冷控制系统

星敏感器探测器用于得到精确的星图数据以解算出高精度的位置、姿态等信息。而星敏感器在轨运行时,需要控制探测器的工作温度,使其工作性能稳定可靠。文章提出了一种基于FPGA的星敏感器探测器制冷控制系统。该系统采用分段式数字PID控制算法生成脉冲宽度调制PWM波驱动半导体制冷器进行高精度制冷,电路结构简单、可靠性高。通过试验验证,该系统具有制冷响应快、超调量小、控温精度高的特点,控温精度可达±0.25℃。     

大视场红外星敏感器折反式光学系统设计

星敏感器是以恒星为探测对象的高精度空间姿态测量装置,广泛应用于卫星、航天飞机、导弹等必备的高精度姿态敏感部件。为了实现在特定环境要求下的精确应用,本文设计了可应用于近红外波长的红外光学系统。首先,根据既定的参数进行了初始结构的选型,并对马克苏托夫望远镜的形式进行了改进。然后,对设计结果进行了探测性能分析。随后对设计好的系统进行了公差分析及优化,使它能满足加工装配需求。最后,为光学系统设计了遮光罩,进行了杂散光分析。设计与分析结果表明：该探测光学系统折反射镜全表面采用球面,系统总长171.2mm,全视场14μm包围能量分布均在86%以上,0.8视场内最大畸变小于4μm。该系统视场大、结构紧凑、装调难度低、探测灵敏度高、探测范围广、温度适应性强,可在0.8～1.9μm近红外波段的宽光谱范围内进行高精度目标检测的准确检测。     

Preparing for space: Increasing technical readiness of low-cost high-performance remote sensing using high-altitude ballooning

Two widely available, small size, weight and power camera systems were flown above 97 % of Earth’s atmosphere and showed utility in single filter vegetation and soil analysis in a space analogue environment. The experiment was conducted as a low-cost verification and test analogue to flying on vastly more expensive low Earth orbit missions. Normalised Difference Vegetation Index (NDVI) was used as the metric by which performance was analysed for ground calibration testing, low and near-space altitude remote sensing. Ground calibration testing with a laboratory-grade spectrometer revealed that both cameras were able to return consistent NDVI results, and high-altitude balloon flight allowed similar data capture from an environment similar to space. Although compressed captured imagery had been processed using gamma correction and pre-image processing, these were able to be corrected provided that access to radiometrically-calibrated data was available. The two hobbyist cameras were shown to return scientifically useful results, demonstrating performance, and additionally their utility for citizen science applications in the near-space environment.     

ESO-based event-triggered attitude control of spacecraft with unknown actuator faults

An event-triggered control strategy based on extended state observer (ESO) is proposed for the attitude tracking problem of small plug-and-play spacecraft with uncertain inertia parameters, external disturbances, and actuator faults. A simplified controller is developed based on the angular velocity and the general disturbances estimated by the provided ESO using the information of the system inputs and the angular velocities. In the designed event-triggered sampling mechanism, a state-dependent event-triggered strategy determines the triggering instant of the controller to reduce the frequency of information transmission between the controller and the actuator. In comparison with the previous literature, this paper considers uncertain inertia parameters, external disturbances, and actuator faults as general disturbances estimated by ESO, especially for the actuator faults. The inputs of ESO are the error of the angular velocities, which can simplify the controller design. Moreover, the designed ESO can effectively attenuate the influence of measured noises generated by the gyroscopes. The proposed event-triggered policy balances the performance of event-triggering and the control stability performance, which reduces the final state convergence regions without increasing more triggering times compared to existing studies. Furthermore, the investigated policy achieves Zeno-free triggering. Numerical simulations verify theoretical results.     

一种新型通用经纬仪检定装置设计

新型通用经纬仪检定装置针对平行光管结构进行了重新优化设计,具有提供瞄准目标、光电自准直和图像采集及处理三大功能.基于图像采集与处理的关键技术,通过CMOS相机光学成像系统实现分划板图像采集,利用图像处理软件解算出特征图像的中心位置,得到被测经纬仪光轴与目标光管光轴的夹角或者自准直的失准值,最终达到用图像识别和软件处理取...     

适用于软体冲击动位移测量的磁敏检测系统

介绍了一种适用于诸如飞行器鸟撞实验的软体冲击动位移检测系统，提出了用霍尔磁敏器件为位移传感元件，新型线性补偿电路为中间处理环节的高频动位移非接触式测量方法。这一测试系统被用于某型号飞行嚣雷达罩的鸟撞实验位移测量中，效果十分理想。