80C31微处理器单粒子效应敏感性地面试验研究

文章针对不同厂家的80C31微处理器,利用重离子、锎源模拟源进行单粒子效应地面试验研究。详细介绍了80C31微处理器单粒子效应试验原理、试验方法、试验系统的软硬件组成以及试验取得的结论。通过试验研究获得了80C31微处理器单粒子翻转和单粒子锁定特征参数。研究结果可为被测器件在卫星型号的使用提供技术参考依据。     

月球探测器动力下降段最优轨迹参数化方法

为保证月球探测器进入姿态调整段时具有充分的高度与速度余量,本文提出一种基于控制变量参数化的月球探测器动力下降段最优轨迹求解方法。在三维探测器软着陆动力学模型基础上,将月球探测器软着陆制导律设计等效为燃料最优约束下的探测器俯仰角控制问题,利用控制变量参数化(Control Variables Parameterization, CVP)方法将该控制问题中的控制变量与约束条件转化为非线性规划问题求解,并引入时间尺度变换,将着陆时间序列加入待规划参数,进而求得满足精度的最优数值解。蒙特卡罗仿真实验表明,与传统的显式制导律相比,本文提出的参数化制导方法在动力下降段燃料更省,动力下降段的起始高度在±20%范围内波动时,仍能以高精度速度和高度指标完成末制导。     

基于压电叠层作动器的柔性自旋导弹振动控制

针对柔性自旋导弹弹性振动问题,提出将压电叠层作动器应用于导弹弹性振动控制方法。将导弹简化为非均匀自由-自由Timoshenko梁模型,考虑陀螺效应和推力作用,将压电叠层作动器应用于导弹弹性振动,基于有限元方法建立含有压电叠层作动器的柔性自旋导弹动力学模型,同时设计模糊滑模控制器,对质量偏心引起的不平衡响应进行数值仿真,通过与不同控制方法进行对比,验证该方法的有效性。     

嫦娥五号探测器多舱段间接力式校时及误差控制方法

为优化嫦娥五号探测器操控,达到通过给任意具备测控链路的舱段校时即可实现多舱段组合体时间同步的目标,提出了一种接力式校时及误差控制方法。该方法通过相邻舱段间接力式时间传递实现舱段间时间自流动。设计了基于飞行模式的时间基准设备检索方法,通过统一的检索配置表使各设备能够根据飞行模式识别上级时间基准设备,实现了各舱段的自主校时。设计了总线控制器(Bus controller,BC)与远置单元(Remote terminal,RT)间的分布式时间传递误差控制方法,BC端修正时间信息发送时产生的误差,RT端控制时间信息接收时引入的误差,保证了整器时统精度。研究方法实现了多舱段复杂航天器的器内自组织时统,已在嫦娥五号探测器上得到应用并取得预期效果,可为后续航天器软件设计提供参考。     

Design of Drilling and Riveting Multi-functional End Effector for CFRP and Aluminum Components in Robotic Aircraft Assembly

To fulfill the demands for higher quality,efficiency and flexibility in aviation industry,a multi-functional end effector is designed to automate the drilling and riveting processes in assembling carbon fiber reinforced polymer(CFRP)and aluminum components for a robotic aircraft assembly system.To meet the specific functional requirements for blind rivet installation on CFRP and aluminum materials,additional modules are incorporated on the end effector aside of the basic processing modules for drilling.And all of these processing modules allow for a onestep-drilling-countersinking process,hole inspection,automatic rivet feed,rivet geometry check,sealant application,rivet insertion and installation.Besides,to guarantee the better quality of the hole drilled and joints riveted,several online detection and adjustment measures are applied to this end effector,including the reference detection and perpendicular calibration,which could effectively ensure the positioning precision and perpendicular accuracy as demanded.Finally,the test result shows that this end effector is capable of producing each hole to a positioning precision within ±0.5 mm,aperpendicular accuracy within 0.3°,a diameter tolerance of H8,and a countersink depth tolerance of±0.01 mm.Moreover,it could drill and rivet up to three joints per minute,with acceptable shearing and tensile strength.     

Development and Prospectives of Ultra-High-Speed Grinding Technology

Ultra-high-speed grinding(UHSG)is a significant and powerful machining method in view of the enhanced productivity and precision demands.Previous researches regarding formation mechanisms and crucial technologies are comprehensively and thoroughly summarized to highlight state-of-art technology of UHSG.On the basis of the interdependence between process and machine innovations,theoretically,grinding mechanisms in strain hardening,strain rate strengthening,thermal softening,size effect and process characteristics need more in-depth studies to clarify the dominance of UHSG.Technically,CFRP wheel integrating with the brazed bonding has a prominent advantage in bonding strength and grit′s configuration over vitrified bonding,which would be superior in UHSG.Furthermore,external high pressure cooling combining with inner jet cooling methods,accompanied by scraper plates to alleviate the effect of air boundary,are crucial and practical measures for realizing effective cooling in UHSG.Grinding processes,especially those being related to grinding parameters and precise in-process measuring approaches,are also prerequisite for fitting and investigation of UHSG.     

Statistical study of energetic electrons in Jupiter’s inner magnetosphere by Juno/JEDI

The Juno spacecraft made the first in-situ observations of energetic particles in the polar region of Jupiter’s magnetosphere. After Jupiter Orbit Insertion (JOI) in July 2016, data from ~20 Juno perijoves (PJs) obtained by Juno/JEDI are accumulated, providing an excellent opportunity to study the long term spatio-temporal distribution of energetic particles in Jupiter’s radiation belt. We transform Juno’s position from a Cartesian to a magnetic coordinate system by tracing magnetic field lines based on a fourth order Runge-Kutta method. Then the fluxes of energetic electrons from PJ1 to PJ14 sorted by different locations in magnetic coordinate space and the data are well organized by the L-shell parameter. The variation of electron flux increases with L-shell. The deviation (the ratio of the 75th percentile to the 25th percentile) of 0.51 MeV electron flux varies from a factor of 1.23 near L = 9.5 to 27.57 near L = 15.5. However, the mean flux decreases by about one order of magnitude in the same region. The electron spectra at larger L-shells are softer than that at smaller L-shells. On the other hand, the electron flux decreases more rapidly with increased L-shell when the location is off the equator. Along an L-shell, the electron flux decrease at first and then increase again from equator to mid-latitude region. In addition, we compare the statistical results with the widely used GIRE2 model. JEDI data correspond well with the GIRE2 model when the L-shell is > 14.75. GIRE2 underestimate the electron flux for L-shell smaller than 13.25. These results of this analysis are applicable to estimate the effects of the radiation environment in Jupiter’s magnetosphere.     

基于CATIA/CAA飞机蒙皮边缘连接孔最小边距快速检测方法

在新机研制阶段,设计部门提供的工程数据集可能存在连接孔边距不符合规范要求,也可能出现连接孔进入零件的R区等现象.通过对边距的检测可以检查连接孔边距的缺陷,因此边距的快速检测是一个重要问题.提出了边距提取和最小边距快速检测的算法,利用CAA/CATIA开发平台,开发了蒙皮边缘孔最小边距的快速检测软件可快速筛选不符合要求的蒙皮边缘孔并标注出来,减少了飞机生产过程中不必要的浪费,提高了生产效率.     

单孔容腔瞬态充气换热的理论分析方法

换热对于容腔瞬态响应过程有显著影响，而目前缺乏分析容腔瞬态过程换热的通用方法，导致容腔瞬态响应模拟精度较差。针对这一现状，基于自由射流、冲击射流及外掠平板换热理论，提出了一种模拟非绝热单孔容腔瞬态充气过程换热的理论方法。应用该方法模拟了容腔压力和温度的瞬态响应过程，并与试验数据进行了对比。结果表明：该理论方法的模拟结果与试验数据吻合很好，压力最大相对误差不超过3%，温度最大相对误差不超过1%，验证了理论方法的可行性和准确性。而绝热模型的模拟结果与试验数据相比，压力和温度的最大相对误差分别可达12%和14%，等温模型的压力和温度的最大相对误差分别可达6%和7%，说明理论方法显著提高了容腔瞬态响应模拟精度。同时，理论分析方法不仅具有较强的通用性，还能够极大地降低分析容腔瞬态换热的成本，可以有效支撑空气系统非绝热容腔元件建模。     

扩频通信系统相偏纠正的一种新方案

文章提出一种新方案,利用同步扩频码不携带载波相位信息的特点来进行相偏纠正的算法避免了相位模糊,可以纠正[0,2π]内的任意相偏,不需要采用锁相环等硬件来实现。