The Cassini Cosmic Dust Analyzer

The Cassini-Huygens Cosmic Dust Analyzer (CDA) is intended to provide direct observations of dust grains with masses between 10⁻¹⁹ and 10⁻⁹ kg in interplanetary space and in the jovian and saturnian systems, to investigate their physical, chemical and dynamical properties as functions of the distances to the Sun, to Jupiter and to Saturn and its satellites and rings, to study their interaction with the saturnian rings, satellites and magnetosphere. Chemical composition of interplanetary meteoroids will be compared with asteroidal and cometary dust, as well as with Saturn dust, ejecta from rings and satellites. Ring and satellites phenomena which might be effects of meteoroid impacts will be compared with the interplanetary dust environment. Electrical charges of particulate matter in the magnetosphere and its consequences will be studied, e.g. the effects of the ambient plasma and the magnetic field on the trajectories of dust particles as well as fragmentation of particles due to electrostatic disruption.The investigation will be performed with an instrument that measures the mass, composition, electric charge, speed, and flight direction of individual dust particles. It is a highly reliable and versatile instrument with a mass sensitivity 10⁶ times higher than that of the Pioneer 10 and 11 dust detectors which measured dust in the saturnian system. The Cosmic Dust Analyzer has significant inheritance from former space instrumentation developed for the VEGA, Giotto, Galileo, and Ulysses missions. It will reliably measure impacts from as low as 1 impact per month up to 10⁴ impacts per second. The instrument weighs 17 kg and consumes 12 W, the integrated time-of-flight mass spectrometer has a mass resolution of up to 50. The nominal data transmission rate is 524 bits/s and varies between 50 and 4192 bps.This revised version was published online in July 2005 with a corrected cover date.     

航空发动机燃油与控制系统的研究与展望

归纳和分析了国内外军用航空发动机燃油与控制系统的研制现状和今后的发展方向 ,简要介绍和评述了主燃油控制、加力燃油控制、尾喷口控制、防喘控制、发动机状态监视 ,特别是FADEC系统的技术特点、方案选择和研究动向。从中可以看出 ,这些方面的技术进步推动了航空发动机的发展     

Autonomous Control Reconfiguration of Aerospace Vehicle Based on Control Effectiveness Estimation

未来空天飞行器跨空天两域飞行,要求有较高的自主性以适应由故障和环境变化带来的不确定因素。针对空天飞行器的不确定性,提出了自主控制重构方案。研究了线性模型的时变控制效益的估计方法,提出并证明了效益矩阵可估计的充分条件,给出了相应的算法并证明了其收敛性和对噪声的鲁棒性;提出了基于线性规划和模糊逻辑的控制分配算法,通过冗余效应器实现了不确定条件下的自主控制重构。系统集成和仿真结果分析验证了方案和算法的有效性。     

战略储备系统备件最优储备量计算的解析方法

 首先简要介绍了战略储备系统及其寿命过程。然后从分析系统的寿命过程入手,将其寿命过程分为两个阶段,每个阶段分别用一连续时间马尔可夫链来描述系统的动态过程,在此基础上给出了战略储备系统最优战略储备量计算的解析方法,并针对不可修的情况给出了简化的计算公式。     

BLOCK DIAGONAL FORM AND BLOCK DIAGONAL CONTROLLER OF NONLINEAR SYSTEMS

G.Meyeretal[l~3Jdescribedthemotionofahelicopterasablocktrianglesystem(BTS),makingitdifferentfromageneralaffinenonlinearsystem.Uptonow,itistruethatBTScanbeexactlylinearized.Thus,thefirstproblem(whetherlinearizableornot)thatfacestheengineerissolved.Thesecondoneishowtoobtainatransformation.AccordingtothefeatureofBTS,MeyeretalconstructedWT-mappingandsolvedtheproblemeasily.Afterhavingstudiedtheequationsofmotionofamissile,theauthorsdiscoveredthatthemodelcalledblockdiagonalnonlinearsystem(BDN…     

卫星姿态跟踪系统的鲁棒控制器设计

研究了具有参数不确定性和外部干扰的卫星姿态跟踪控制问题。针对这一类多输入／多输出不确定非线性系统，提出了一个基于不确定项上界的鲁棒输出跟踪控制器设计方法。应用输入／输出反馈线性化法和李亚普诺夫方法，设计了一个控制律，它可确保系统输出按指数规律跟踪期望输出。该控制器计算简单，易于实现。仿真结果表明：即使系统存在不确定性，仍可在闭环系统中实现精确的姿态控制。     

多级飞行控制系统设计

 现代飞行控制系统设计中,如果同时考虑三轴模型,要实现实时最优控制是非常困难的,因为飞机短周期运动三轴模型阶数通常是七、八阶,要实现最优控制,就得实时求解相应维数的Riccati方程,这对于阶数较高的系统是非常困难的,甚至根本无法实现。但是,如果系统维数很低,实时求解相应维数的Riccati方程则可望实现。因此,将原高阶系统分解成若干相互关联的子系统,进行递阶分级控制,这样子系统的维数将大大低于原系统维数,并且各子系统的最优控制计算可分别由各子系统的计算机完成。由此,飞行控制系统的最优设计实现将成为可能。     

金属板料单向拉伸引伸计及测试系统的研制

利用电阻应变式传感器的原理，研制了单向引伸计及测试系统，对金属薄料的成形性能参数应变刚指数n和厚向异性指数r进行检测，并成功地用于科研和教学活动中，在材料检测研究方面颇具价值。     

基于Riccati方程的离散容错控制系统设计

基于离散系统的Ｒｉｃｃａｔｉ方程，提出一种对传感器失效具有完整性的离散控制系统的设计方法，给出了完整性设计方法的设计步骤，并用设计实例验证了该方法的有效性．该方法还可推广用于执行器失效的情况．     

FMS实时调度系统的研究

柔性制造系统（ＦＭＳ）运行控制软件是保证ＦＭＳ有条不紊运行并充分发挥其潜在能力和效益的指挥中心，而ＦＭＳ运行软件的核心是实时调软件。本文讨论了面向对象的方法和专家系统技术在ＦＭＳ实时高度软件设计中的应用。该设计技术既能发挥面向对象方法的优势，又能突出专家系统的特点，以对象为中心来构造专家系统，本评论人知识获取、表示和推理三方面进行了论述，重点介绍了ＦＭＳ调度领域专家知识的面向对象表示。