GEO卫星基于电推进系统的倾角与偏心率联合控制方法

针对配置电推力器的GEO卫星位置保持问题,提出一种对倾角与偏心率进行联合控制的方法,建立了求解控制方程的优化模型,并针对优化模型变量多、约束复杂的问题进行降维处理,得到两种简化的求解方法,降低了求解复杂度与计算量,适合星上自主计算。采用联合控制方法,仅靠电推力器就能够同时实现卫星倾角和偏心率的高精度控制,有效降低卫星位置保持总的推进剂消耗。仿真算例表明,与电推力器只控倾角的传统方法相比,在保证偏心率控制精度不变的前提下,采用电推力器倾角与偏心率联合控制方法,15年寿命期内节省推进剂质量39kg。     

基于组合赋权的空管系统安全风险物元评价

空管系统的安全风险状况对航空运输安全运营有直接的影响。综合考虑空管系统安全运行管理的特点,构建空管系统安全风险的评价指标体系;应用欧几里得距离函数对空管系统安全风险评价指标进行组合赋权,确定空管系统安全风险评价指标的组合权重;引入物元分析方法建立空管系统安全风险评价物元模型,并进行实例验证。结果表明:物元分析方法能够评估空管系统整体的安全风险状况,得到了各个评价指标的安全风险状况,有助于采取针对性的有效措施提高空管部门的安全风险管理水平。     

惯导系统结构拓扑优化方法研究

针对惯导系统结构拓扑优化问题,提出了一种考虑多工况组合和等效边界处理的优化方法.以惯导系统结构件为研究对象,梳理了不同结构件的载荷工况;以刚度最大为 目标函数,以体积分数、结构频率和最大变形等作为约束条件,研究了变密度拓扑优化方法;以某惯导系统的盖板、惯性台体和外壳体3个结构件为例,进行了优化方法验证.结果表明,与传统...     

基于M-W组合的中长基线RTK定位方法研究与实现

介绍一种实现GPS中长基线实时动态(RTK)定位的方法,研究基于M-W组合搜索双频GPS载波相位模糊度的方法,最终使用消电离层LC载波相位组合观测量进行相对定位。车载试验结果表明,对于双频GPS接收机,流动站距离基准站50km以内,使用本方法RTK定位可以达到5cm(RMS)的点位精度。     

单舰武器系统组合抗击反舰导弹的方案选优

通过对单舰各武器系统抗击反舰导弹的变换系数、对空防御综合因子、火力指数、通道因子等分析,建立各种组合抗击反舰导弹解析作战能力指数模型,结合"费效比"比较,得到选优方案;通过用蒙特卡洛法来对某型舰艇抗击两种型号的反舰导弹进行实例计算,得到各种抗击组合方案的作战能力指数和"费效比";经过仔细比较,提出了电子对抗系统、舰空导弹武器系统和近程防御武器系统的抗击组合是最优抗击组合方案的观点.     

Adaptive controller design for satellite attached by non-cooperative object

When non-cooperative body attachment occurs in space, the inertia of the new combination and the change of the system’s momentum are unknown. This uncertainty may lead to the instability of the spacecraft’s attitude control. In order to solve this problem, we propose an adaptive control scheme based on the inertia estimation of the new, combined system of non-cooperative body and satellite. This method can allow the new combination of different situations to reach a stable state with a high level of precision and speed. In this paper, the stability of the adaptive control scheme is proven by constructing a Lyapunov function. A simulation environment in which a non-cooperative body attaches to a satellite attaches to is constructed. The simulation shows that the attitude error converges to a small field when using the control scheme, regardless of unfavorable cases, including unknown inertia parameters, added momentum. In addition, the simulation results show the strong robustness of the control scheme for the new combination.     

Improvement of the GRACE star camera data based on the revision of the combination method

The new release of the sensor and instrument data (Level-1B release 02) of the Gravity Recovery and Climate Experiment (GRACE) had a substantial impact on the improvement of the overall accuracy of the gravity field models. This has implied that improvements on the sensor data level can still significantly contribute to arriving closer to the GRACE baseline accuracy. The recent analysis of the GRACE star camera data (SCA1B RL02) revealed their unexpectedly higher noise. As the star camera (SCA) data are essential for the processing of the K-band ranging data and the accelerometer data, thorough investigation of the data set was needed. We fully reexamined the SCA data processing from Level-1A to Level-1B with focus on the combination method of the data delivered by the two SCA heads. In the first step, we produced and compared our own combined attitude solution by applying two different combination methods on the SCA Level-1A data. The first method introduces the information about the anisotropic accuracy of the star camera measurement in terms of a weighing matrix. This method was applied in the official processing as well. The alternative method merges only the well determined SCA boresight directions. This method was implemented on the GRACE SCA data for the first time. Both methods were expected to provide optimal solution characteristic by the full accuracy about all three axes, which was confirmed. In the second step, we analyzed the differences between the official SCA1B RL02 data generated by the Jet Propulsion Laboratory (JPL) and our solution. SCA1B RL02 contains systematically higher noise of about a factor 3–4. The data analysis revealed that the reason is the incorrect implementation of algorithms in the JPL processing routines. After correct implementation of the combination method, significant improvement within the whole spectrum was achieved. Based on these results, the official reprocessing of the SCA data is suggested, as the SCA attitude data are one of the key observations needed for the gravity field recovery.     

计算机辅助功能危险评估方法研究

功能和安全一直是高风险复杂系统的关键问题。传统的功能危险评估由安全工程师手工进行分析，面对高度复杂系统时，就会变得难以完成且容易出错。解决这种问题的一个途径就是利用计算机进行辅助。为此提出一种计算机辅助的功能危险评估方法，采用状态图语言搭建系统状态模型，将功能失效影响直观地从系统状态转移图上表达出来。并且在系统状态模型的基础上，采用计算机编程快速计算出导致系统故障的失效组合以及最小割集。最后以飞机为对象证明了方法的可行性。     

星载二次电源的电磁兼容预设计

针对星载二次电源电磁兼容试验中辐射发射的超标问题,提出了电磁兼容预设计方法.分析二次电源电磁干扰产生的机理,利用SPICE仿真器建立传导干扰的电路等效模型,优化电路设计得到传导干扰源;应用修正的单线模型近似计算辐射干扰,根据计算结果,利用遗传算法优化等效偶极子的数目和分布位置建立场等效模型;基于场路结合的方法,以传导干...