大机动飞行情况下姿态控制系统的设计

本文针对目前战术导弹广泛使用捷联系统这个现状,以及对大机动飞行器采用姿态角误差反馈进行控制有时出现的奇异问题,提出并研究了基于四元数进行大机动战术导弹姿态控制系统的设计问题.首先,给出了大机动飞行情况下基于四元数描述的弹体动力学模型,然后,基于非线性控制系统综合方法设计了姿态控制系统,并验证了系统的稳定性.研究结果表明,基于四元数进行姿态控制系统的设计,既解决了姿态角表示法存在的奇异性问题,又可减少捷联计算机的计算量,对战术导弹具有重要实际意义.最后,通过数值仿真验证了本文提出方法的有效性.     

充液航天器液体晃动等效力学模型的建立

在考虑液体表面张力影响液体晃动求解的基础上,利用动力学方程等价准则,建立了三轴定向充液卫星在二维平动和二维摆动扰动作用下的空间摆等效力学模型,并对两种情况下等效摆的主要参数进行了计算和比较。结果表明,考虑表面张力时,液体的晃动特性对航天器姿态控制系统稳定性有不利影响。     

扩展旋转矢量捷联姿态算法

给出了一种新的旋转矢量捷联姿态构造算法，该算法由陀螺样本的多重积分来构造旋转矢量的最小二乘估计。新算法具有较好的顺序递推结构，易于在机载计算机上编程实现，比传统方法更容易满足一些限制较多的特殊应用。文中还给出了该算法在机载计算机上的计算流程及算法的局部硬件化实现。     

Energy Spectrum of Galactic 10–100 MeV Protons in Quiet Sun Periods

The dynamics of the proton energy spectrum during the solar cycle is studied. The spectra were determined by 1–100 MeV particle fluxes measured by different instruments mounted aboard the Earth's IMP-8 satellite for more than one hundred quiet-time intervals in the period between 1974 and 1991. The galactic branch of the spectra (E _p > 10 MeV) constructed for every quiet interval was fitted by a power law function, J =CE . The theory predicts that in the 1–100 MeV energy range, where the adiabatic cooling of particles is dominant, = 1, while we have derived a double-peak distribution. The main maximum has the mean value = 1.35. The mean value of the second, much weaker maximum, is = 0.95. Within the main maximum, values are distributed in accordance with the Gaussian law with a standard deviation D/ = 0.12. The substantial difference of from unity requires the elaboration of a new model of modulation processes in the inner heliosphere. The values corresponding to the second maximum show that modulation processes correspond sometimes to theoretical conceptions. It is shown that correlates weakly with parameters A and describing the solar branch of the spectrum (J(E) = AE ^–). At the same time, a more significant correlation is observed between and the solar activity index, R _z, the counting rate of the Deep River neutron monitor, and the energy value in the minimum of the energy spectrum flux, E _min.     

球形铝粉对低燃速丁羟推进剂燃烧特性的影响

采用静态燃烧性能测试和实验发动机动态实验等方法。研究了球形铝粉替代非球形铝 后推进剂燃速特性的变化。研究发现，含球形铝粉推进剂的低压燃烧速显著降低，而燃速压强指数明显高于含非球形铝粉推进剂，讨论了球形和非球形铝粉对推进剂燃烧过程的影响，并初步解释了含球形铝粉推进剂低压燃速的下降原因。     

航天飞行器防热部件烧蚀行为的数值模拟

对航天飞行器防热部件在氧－煤油发动机火焰喷吹下的烧蚀行为进行了有限元数值模拟。利用“杀死”单元的方法建立防热部件瞬态温度场的有限元模型，实现了烧蚀边界的退缩，从而完成了对烧蚀尺寸变化的定量描述。烧蚀开始于4．59s，到12s时线烧蚀量为1．47mm。计算结果与试验的实测结果一致。     

机动再入飞行器的复合制导方案研究

对机动再入飞行器弧段的复合制导方案进行了研究，首先提出了通过高低空复合制导控制再入飞行器的终端速度和弹道倾角的思路；然后分别给出了高空最优制导律和大气厚再入最优制导律；最后对此复合制导方案进行了数字仿真。仿真结果表明此方案在理论上是可行的。     

LISA — a study of the ESA cornerstone mission for observing gravitational waves

The primary objective of the Laser Interferometer Space Antenna (LISA) mission is to detect and observe gravitational waves from massive black holes and galactic binaries in the frequency range 10⁻⁴ to 10⁻¹ Hz. This low-frequency range is inaccessible to ground-based interferometers because of the unshieldable background of local gravitational noise and because ground-based interferometers are limited in length to a few km. LISA is an ESA cornerstone mission and recently had a system study (Ref. 1) carried out by a consortium led by Astrium, which confirmed the basic configuration for the payload with only minor changes, and provided detailed concepts for the spacecraft and mission design. The study confirmed the need for a drag-free technology demonstration mission to develop the inertial sensors for LISA, before embarking on the build of the flight sensors. With a technology demonstration flight in 2005, it would be possible to carry out LISA as a joint ESA-NASA mission with a launch by 2010 subject to the funding programmatics. The baseline for LISA is three disc-like spacecraft each of which consist of a science module which carries the laser interferometer payload (two in each science module) and a propulsion module containing an ion drive and the hydrazine thrusters of the AOCS. The propulsion module is used for the transfer from earth escape trajectory provided by the Delta II launch to the operational orbit. Once there the propulsion module is jettisoned to reduce disturbances on the payload. Detailed analysis of thermal and gravitational disturbances, a model of the drag-free control and of the interferometer operation confirm that the strain sensitivity of the interferometer will be achieved.     

自适应控制方法的直接命中目标本体的平行接近制导律

本文在最少量测条件下采用视线角速度ｑ趋于零的指标函数和低阶等效辨识模型与快速自适应控制方法实现了战术导弹的平行接近制导律。这种最优制导律可以实现直接命中目标本体，实现一弹多用，可以用于反导弹的控制。能使制导装置简化并使其尺寸和重量减小，算法简单易于工程使用。经过大量数学和半实物仿真试验表明，上述成果可应用于实际工程当中。     

管道—楔形肋片式空间辐射器性能计算

在航天器热控制中，空间辐射器是最主要的排热部件。本文对双面及单面管道—楔形肋片式空间辐射器进行了详细的热分析，并完成了管道—楔形肋片式空间辐射器的性能计算