反高斯分布环境因子估计

研究了反高斯分布环境因子估计。根据指数分布和对数正态分布环境因子的定义及数据折算与综合的方便,给出了反高斯分布环境因子的定义。据此定义,用经典方法和贝叶斯方法推证了环境因子的上、下限,并给出了一些近似式以便于计算。实例计算结果较令人满意。     

A formulation of multitarget tracking as an incomplete data problem

Traditional multihypothesis tracking methods rely upon an enumeration of all the assignments of measurements to tracks. Pruning and gating are used to retain only the most likely hypotheses in order to drastically limit the set of feasible associations. The main risk is to eliminate correct measurement sequences. The probabilistic multiple hypothesis tracking (PMHT) method has been developed by Streit and Luginbuhl in order to reduce the drawbacks of "strong" assignments. The PMHT method is presented in a general mixture densities perspective. The Expectation-Maximization (EM) algorithm is the basic ingredient for estimating mixture parameters. This approach is then extended and applied to multitarget tracking for nonlinear measurement models in the passive sonar perspective.     

环面Fuchs方程解的性质及其可积性

研究环面Ｔ＾２上只有一个正则奇点的Ｆｕｃｈｓ方程，得到了参数ｒ＝６时，方程有一个椭圆函数解，其任何解皆为半纯函数，以及方程的单值群为可解群的结果。在此基础上，将Ｒｉｅｍａｎｎ球面上Ｆｕｃｈｓ方程的可积性概念推广到环面上，并得到一系列环面Ｆｕｃｈｓ方程都是可积的结果。     

高安全分区信息物理系统的仿真验证研究

信息物理系统(CPS)强调借助网络对物理世界的感知和控制,往往系统规模较大、结构复杂,通常重视对系统开发前、中期的验证工作,而高安全的CPS对验证的要求更高。在实现分区调度、通信等服务的基础上,通过构建Windows平台上的模拟分区环境,我们完成了某高安全信息物理系统的建模,检验系统设计的可调度性、故障恢复能力等行为特性,从而验证了研究方法的合理性和正确性。     

Analytic estimation and numerical modeling of actively cooled thermal protection systems with nickel alloys

Actively cooled thermal protection system has great influence on the engine of a hypersonic vehicle, and it is significant to obtain the thermal and stress distribution in the system. So an analytic estimation and numerical modeling are performed in this paper to investigate the behavior of an actively cooled thermal protection system. The analytic estimation is based on the electric analogy method and finite element analysis（FEA） is applied to the numerical simulation. Temperature and stress distributions are obtained for the actively cooled channel walls with three kinds of nickel alloys with or with no thermal barrier coating（TBC）. The temperature of the channel wall with coating has no obvious difference from the one with no coating, but the stress with coating on the channel wall is much smaller than that with no coating. Inconel X-750 has the best characteristics among the three Ni-based materials due to its higher thermal conductivity, lower elasticity module and greater allowable stress. Analytic estimation and numerical modeling results are compared with each other and a reasonable agreement is obtained.     

Multi-sensor control for precise assembly of optical components

In order to perform an optical assembly accurately, a multi-sensor control strategy is developed which includes an attitude measurement system, a vision system, a loss measurement system and a force sensor. A 3-DOF attitude measuring method using linear variable differential transformers （LVDT） is designed to adjust the relation of position and attitude between the spher- ical mirror and the resonator. A micro vision feedback system is set up to extract the light beam and the diaphragm, which can achieve the coarse positioning of the spherical mirror in the optical assembly process. A rapid self-correlation method is presented to analyze the spectrum signal for the fine positioning. In order to prevent the damage of the optical components and realize sealing of the resonator, a hybrid force-position control is constructed to control the contact force of the optical components. The experimental results show that the proposed multi-sensor control strategy succeeds in accomplishing the precise assembly of the optical components, which consists of parallel adjustment, macro coarse adjustment, macro approach, micro fine adjustment, micro approach and optical contact. Therefore, the results validate the multi-sensor control strategy.     

民用飞机试飞规划与管理系统的评估研究

国内某民机型号的飞行试验工作者们根据数年的工作经验,开发了基于民机飞行试验的规划与管理系统(Flight Test Control System,简称FTCS),以利于民机各项试飞工作的开展。相比于一般的信息管理系统,FTCS系统具有更多行业本身的特质,在对本系统的一些重要功能进行体验后,从定性与定量的角度对系统进行评估,建立一套适用于民机试飞优化系统的评估方法,利于后续类似系统延续其优秀的设计长处,改进本系统存在的不足,为未来民机试飞系统的开发提供参考和借鉴。     

用于立方体卫星的高增益天线技术与发展趋势

随着MarCO与RainCube的成功在轨验证,立方体卫星已经在深空探测与遥感领域展现出独特的优势。立方体卫星搭载的天线不仅需要提供良好的辐射特性,还必须满足立方体卫星苛刻的体积和重量限制,这种限制条件在设计大口径高增益天线时尤为重要。首先简要介绍了立方体卫星的起源、发展及其应用前景,其次重点介绍了立方体卫星高增益天线的技术特点、研究现状及其在轨验证情况,最后归纳总结了立方体卫星高增益天线技术的未来发展趋势,为我国后续开展立方体卫星研究与应用提供参考。     

民机特情乘务训练模拟软件的设计研究

为提高飞行乘务员在民机飞行过程中处理事故的应对能力,消除因人为因素产生的损失,保证飞行的安全性,根据2003年中国国际航空公司编制的飞行乘务员培训大纲中关于乘务应急生存训练内容,提炼出了关于乘务应急生存训练的框架,介绍了编制飞行乘务员应急培训所需要培训模拟软件的设计思路,以期为民机的安全飞行提供技术保障支持。