飞机燃油箱系统关键设计构型控制研究

飞机燃油箱系统关键设计构型控制限制是适航限制项目的组成部分,是一种强制性适航维修项目。分析和研究了确定关键设计构型控制的方法和要求。     

采用变速控制力矩陀螺的航天器姿态跟踪研究

研究了以变速控制力矩陀螺(VSCMG)作为执行机构的航天器姿态跟踪问题.建立了以VSCMG为执行机构的航天器姿态动力学模型, 引入一阶稳定的线性角速度滤波方程, 同时, 根据Lyapunov稳定性定理, 设计了闭环系统的控制律. 利用加权的最小范数解得到VSCMG的姿态控制输入矢量. 提出了表征VSCMG构型的新奇异度量, 在其基础上利用梯度法构建了VSCMG的零运动, 以回避VSCMG的构型奇异, 并使转子转速趋于期望值. 以四陀螺金字塔构型为例进行仿真,仿真结果验证了该算法的可行性和有效性.      

深空大规模天线阵布局优化方法研究

由大量廉价的小型反射面天线组成阵列对航天器进行跟踪通信是未来深空测控网发展 的一条新思路。提出一种改进的遗传算法对大规模小天线阵列地理布局进行优化,提高天线 阵列的测控性能。首先分析了布局优化的约束条件,然后以最小化旁瓣电平为目标,建立了 优化模型。分析了Kogan梯度算法和常规遗传算法的局限性,最后给出了改进遗传算法的优 化流程。仿真结果表明,改进的遗传算法不但具有高的优化效率,还可应用于阵列布局的多 目标优化。
     

控制力矩陀螺群奇异角动量超曲面仿真分析

用角动量超曲面仿真分析了控制力矩陀螺构型奇异的产生机理。基于控制力矩陀螺群动力学总角动量和输出控制力矩,讨论了典型构型奇异存在的状况,并确定了奇异点存在的判断依据,对五棱锥构型的显奇异和隐奇异进行了角动量超曲面仿真,发现能通过零运动脱离奇异状态的隐奇异点,为控制力矩陀螺群的操纵律设计提供了重要依据。控制系统数学仿真结果表明该分析法有效。     

偶数重连续覆盖的Walker星座设计方法

针对期望覆盖重数为偶数重时连续覆盖Walker星座的构型设计问题,提出一种基于覆盖带理论的构型设计方法。首先分析同轨道卫星组成覆盖带时的构型设计特例,随后将结论推广,改进了传统Walker星座的构型表征形式并提出覆盖带构型参数。基于轨道参数的相平面映射,给出了异轨卫星组成覆盖带时特征宽度的计算方法。通过分析相平面上覆盖带的拼接情况,给出了轨道倾角的优化策略和偶数重覆盖任意纬度的Walker星座设计步骤。所提出方法能显著提高构型枚举效率,且能满足不同纬度范围的覆盖需求。仿真表明,该方法能减少约10%覆盖所需的卫星数量,并能通过调整构型参数进一步优化轨道面数量。     

我国自旋稳定通信卫星四种发展方案的比较

以国外自旋稳定通信卫星发展的技术途径为背景,比较了在“东方红二号甲”卫星技术的基础上进一步发展中国自旋稳定通信卫星的不同技术方案;说明方案的选择主要取决于对今后继续发展自旋稳定通信卫星的战略考虑。     

Landing of the asteroid probe with three-legged cushioning: Planar asymmetric dynamics and safety margin

The probes landing on the surfaces of the asteroids can increase the scientific return of the exploration missions and also promote the development of deep space resources. Because of its excellent applicability to the uneven terrain and a lighter configuration than the four-legged mechanisms, the three-legged cushioning mechanisms are suitable for dissipating the impact energy and then quickly stabilizing the probe attitude when the probe lands on the micro-gravitational surfaces of the asteroids. Research on the landing dynamics of the probe facilitates to the design of the landing-cushioning mechanism and the optimization of its configuration, as well as the assessment of the landing safety. Comparing with the previous extensive related literature focusing on landing dynamics of the probes assisted by the four-legged cushioning mechanisms, this paper studies creatively the planar dynamics considering the asymmetric characteristic and the leg-leg coupling to understand the landing process of the asteroid probe with the three-legged cushioning mechanism and thereby to optimize the configuration of cushioning mechanism and assess safety margin of the landing. According to the touchdown status, the asymmetric landing modes are classified and the coupling issue in the construction of the landing models is explained. Consequently, two types of dynamics models describing the two-stages touchdown cushioning process of the probe are established. Then, five significant configuration factors of the cushioning mechanism are extracted, and their values combinations are designed according to the Taguchi orthogonal method. On this basis, the maximum safe landing attitude angles of the probe are solved by using these values combinations as the input conditions under the dangerous situations in different landing modes. The range analysis and nonlinear fitting methods are employed to discuss the influence of the configuration factors on the landing safety margin, and the favorable parameter values of the configuration factors are determined. Next, the influence of the ground obstacle on the landing safety margin and several methods to improve the margin are researched. Finally, the complete attitude changes of the probe in two representative landing cases are analyzed. The results studied in this paper can contribute to configuration optimization of the three-legged cushioning mechanisms and safety assessment of the legged probes landing on the asteroids, as well as to provide a reference for discussing the leg-leg coupling issue received less attention in landing dynamics of the probes with the four-legged cushioning mechanisms.     

航天器可展开薄膜遮光罩机械设计的发展与展望

从可展开薄膜遮光罩的几何构型、展开驱动技术、薄膜折痕设计和薄膜褶皱动力学分析四个方面论述了航天器可展开薄膜遮光罩机械设计的发展现状和特点，在分析比较的基础上对可展开薄膜遮光罩机械设计的发展趋势进行了展望，旨在为航天器可展开薄膜遮光罩的创新发展提供参考。