弱测量数据下的关机时间估计及其精度分析

通过分析关机后无助推的飞行器落点预报的问题,可以知道落点的精度取决于关机点处的轨道参数,即时间、速度和位置的准确程度,其中关机时间是影响落点精度的主要因素。文章主要研究了在测量数据不完整或缺少的情况下对关机时间的估计问题,并对其精度作了分析,并给出了仿真结果。     

无人机测控传输中SCCPM优化设计

针对无人机测控传输系统频率资源日趋紧张、电磁环境日渐复杂的现状,为提高无线传输频带效率和功率效率,在卷积码和CPM（Continuous Phase Modulation,连续相位调制）的基础上,提出一种基于SCCPM（Serially Concatenated CPM,串行级联CPM）的无人机遥控、遥测数据传输体制.通过引入Turbo（涡轮）码迭代原理设计CPM解调与卷积译码反馈校正结构,并对CPM解调算法进行优化以减小复杂度,得到相位连续、频谱紧凑、编码增益高、收敛特性好的无人机测控通信系统.仿真结果表明：所设计方案采用级联外迭代方式可获取更高的信噪比增益、更低的错误平层——与典型应用的RS（Reed-Solomon,里德-所罗门）码级联卷积码相比,该方案能够多获取1.6 dB的信噪比增益,表明SCCPM更适用于无人机测控数据传输.     

SEA与仿真相结合的高超声速巡航飞行器系统效能评估

SEA方法与工程／交战级攻防对抗仿真相结合的效能评估框架,解决了SEA方法的建模问题。本文应用此框架以高超声速巡航飞行器为例研究了其系统效能,框架中基于测度论提出了效能指标,通过对基于HLA的攻防对抗仿真系统的输出测量,达到评估飞行器系统效能的目标,最后以一个简单的战情为应用对象,使用上述评估框架分析高超声速巡航飞行器的系统效能。     

21世纪的航天(续)

航天事业在20世纪已取得显著进展和辉煌成就。21世纪即将来临。在21世纪,世界航天如何发展、将取得哪些重大成就,是人们关注的话题。为此,笔者根据有关材料汇编了这份材料,以供参考。共4讲,第一、二讲已刊登在本刊1998年第4期,下面为第三、四讲。     

Trajectory tracking control of a VTOL unmanned aerial vehicle using offset-free tracking MPC

Designing a stable and robust flight control system for an Unmanned Aerial Vehicle (UAV) is an arduous task. This paper addresses the trajectory tracking control problem of a Ducted Fan UAV (DFUAV) using offset-free Model Predictive Control (MPC) technique in the presence of various uncertainties and external disturbances. The designed strategy aims to ensure adequate flight robustness and stability while overcoming the effects of time delays, parametric uncertainties, and disturbances. The six degrees of freedom DFUAV model is divided into three flight modes based on its airspeed, namely the hover, transition, and cruise mode. The Dryden wind turbulence is applied to the DFUAV in the linear and angular velocity component. Moreover, different uncertainties such as parametric, time delays in state and input, are introduced in translational and rotational components. From the previous work, the Linear Quadratic Tracker with Integrator (LQTI) is used for comparison to corroborate the performance of the designed controller. Simulations are computed to investigate the control performance for the aforementioned modes and different flight phases including the autonomous flight to validate the performance of the designed strategy. Finally, discussions are provided to demonstrate the effectiveness of the given methodology.     

学生机长训练中的驾驶舱资源管理

本文研究了学生机长训练阶段中如何配置人力资源、营运信息、设备资源和易耗资源,对提高学生机长的驾驶舱资源管理水平提出建议,以最优化资源效用,确保训练安全和质量。     

面向飞行器控制的切换系统分析与综合

面向飞行器控制的切换系统分析与综合是近年来飞行器控制领域的研究热点。从切换系统在飞行器控制领域的优越性出发,首先对线性切换系统的分析与综合给予简单综述,在此基础上分析了切换系统在飞行器控制领域的应用,而后展开论述面向飞行器控制的线性切换系统建模、分析与控制综合方法,重点介绍局部重叠切换系统、稳定性分析和基于切换系统的综合方法等内容。最后,提出面向飞行器控制的切换系统研究的发展趋势。     

准惯性定向探测卫星GPS接收天线安装角度研究

研究了准惯性定向探测卫星GPS接收天线的安装角度问题. 根据卫星任务需求分析其姿态需求, 再由姿态需求对GPS接收天线的安装方式进行理论分析和仿真计算, 通过GDOP值优选了安装角度方案. 仿真结果表明, GPS接收天线的轴向在本体±y轴即轨道面法向或负法向方向附近.      

基于遗忘因子算法的飞行器颤振模态参数辨识

采用频率响应函数数据的频域多输入多输出状态空间模型,研究基于遗忘因子的输入输出数据矩阵构造机制,提高辨识算法的收敛速度;针对系统矩阵的求解问题,采用主成分分析法实现对模型参数矩阵的一致性估计,避免了奇异值分解带来的估计有偏性;算法前采用新息方差准则估计出系统的阶数,以减少计算复杂度。最后利用试飞试验数据辨识飞行器的系统参数,验证了该方法的有效性。     

Towards a cooperation between the arts,space science research and the European Space Agency – Preliminary findings of the ESA Topical Team Arts and Sciences (ETTAS)

The arts offer alternative insights into reality, which are explored by science in general, and broadened by the activities conducted by the European Space Agency [4] and other space agencies. Similar to the way the members of ESA are ambassadors for spaceflight and science, artists and cultural professionals are ambassadors for human expression, experimentation, and exploration. In June 2011, the ESA Topical Team Arts and Sciences (ETTAS) held a three-day workshop at the European Astronaut Centre in Cologne, Germany. During this workshop, topics and ideas were discussed to develop initiatives between the arts, sciences and ESA. The aim was to foster and expand the human and cultural aspects of space exploration, and at the same time offer a means of communication that aims to reach audiences beyond the scope of traditional space-related channels. The consensus of the team was that establishing and sustaining a transdisciplinary professional community consisting of ESA representatives, scientists and artists would fuel knowledge transfer, and mutual inspiration. Potential ways to provide a sustainable cooperation within and between the various groups were discussed. We present the preliminary findings including a number of measures and mechanisms to initiate and conduct such an initiative. Plausible organisational measures, procedures and consequences, as well as a proposition on how to proceed are also discussed. Overall, the involvement and cooperation between the arts, space science research and ESA will enhance in the citizens of the ESA member states the sense of public ownership of ESA results, and participation in ESA?s research.