某型号机襟翼机构摩擦磨损可靠性分析与计算(英文)

本文应用空间机构的建模方法建立了某型号机襟翼机构运动的数学模型。当给出输入参数时，可通过此数学模型求出襟翼机构的理论输出参数。输入参数相同时，通过引入摩擦磨损量至数学模型可获得襟翼机构的实际输出参数，并在此基础上求得襟翼机构的摩擦磨损可靠性。     

中国核电厂操作员反应时认知模型的应用(英文)

讨论了一些有关人员行为与时间有依赖关系的可靠性模型；给出了中国核电厂操作员在清华大学培训模型机上的一些可靠性实验结果。此外，还根据已获得的实验数据计算了在ＡＴＷＳ事故条件下人的失误概率。     

A formal approach using SysML for capturing functional requirements in avionics domain

In this work, a Model-Based Systems Engineering approach based on SysML is proposed. This approach is used for the capture and the definition of functional requirements in avionics domain. The motivation of this work is triple: guide the capture of functional requirements, validate these functional requirements through functional simulation, and verify efficiently the consistency of these functional requirements. The proposed approach is decomposed into several steps that are detailed to go from conceptual model of avionics domain to a formal functional model that can be simulated in its operating context. To achieve this work, a subset of SysML has been used as an intermediate modelling language to ensure progressive transformation that can be understood and agreed by system stakeholders. Formal concepts are introduced to ensure theoretical consistency of the approach. In addition, transformation rules are defined and the mappings between concepts of ARP4754A civil aircraft guidelines and SysML are formalized through meta-model. The resulting formalization enables engineers to perform functional simulation of the top-level functional architecture extracted from operational scenarios. Finally, the approach has been tested on an industrial avionics system called the Onboard Maintenance System.     

飞机机身近区电磁散射建模研究

采用物理光学法和一致性几何绕射理论，分析机身各 球面波照射下的近场电磁散射特性几何绕射并建立其雷达散射截面（ＲＣＳ）数学模型，同时对于复杂机身的前部，采用面元油、即采用双三次Ｂ样条技术对机外形进行拟合，然后再用一致性几何绕射理论进行计算。种方法具有一定的可信度。     

Controlling factors of Region 2 field-aligned current and its relationship to the ring current: Model results

One essential component of magnetosphere and ionosphere coupling is the closure of the ring current through Region 2 field-aligned current (FAC). Using the Comprehensive Ring Current Model (CRCM), which includes magnetosphere and ionosphere coupling by solving the kinetic equation of ring current particles and the closure of the electric currents between the two regions, we have investigated the effects of high latitude potential, ionospheric conductivity, plasma sheet density and different magnetic field models on the development of Region 2 field-aligned currents, and the relationship between R2 FACs and the ring current. It is shown that an increase in high latitude potential, ionospheric conductivity or plasma sheet density generally results in an increase in Region 2 FACs’ intensity, but R2 FACs display different local time and latitudinal distributions for changes in each parameter due to the different mechanisms involved. Our simulation results show that the magnetic field configuration of the inner magnetosphere is also an important factor in the development of Region 2 field-aligned current. More numerical experiments and observational results are needed in further our understanding of the complex relationship of the two current systems.     

Reliable flight performance assessment of multirotor based on interacting multiple model particle filter and health degree

Multirotor has been applied to many military and civilian mission scenarios. From the perspective of reliability, it is difficult to ensure that multirotors do not generate hardware and software failures or performance anomalies during the flight process. These failures and anomalies may result in mission interruptions, crashes, and even threats to the lives and property of human beings. Thus, the study of flight reliability problems of multirotors is conductive to the development of the drone industry and has theoretical significance and engineering value. This paper proposes a reliable flight performance assessment method of multirotors based on an Interacting Multiple Model Particle Filter (IMMPF) algorithm and health degree as the performance indicator. First, the multirotor is modeled by the Stochastic Hybrid System (SHS) model, and the problem of reliable flight performance assessment is formulated. In order to solve the problem, the IMMPF algorithm is presented to estimate the real-time probability distribution of hybrid state of the established SHS-based multirotor model, since it can decrease estimation errors compared with the standard interacting multiple model algorithm based on extended Kalman filter. Then, the reliable flight performance is assessed with health degree based on the estimation result. Finally, a case study of a multirotor suffering from sensor anomalies is presented to validate the effectiveness of the proposed method.     

同伦法在现代飞机尾旋预测中的应用

在利用ＢＡＣＴＭ法对高性动性能飞机尾旋预测中，首先要求解平衡解，为此需要使用静态，强迫振荡天平气动模型和旋转天平气动模型，而在两气动模型转换过程中，常常遇到难找或不断得到平衡解的问题，针对这一问题，利用同伦法对气动模型进行处理，有效地了解决了该问题，同时，结合某战斗机进行了有关尾旋的计算和预测，结果表明，所提出的方法是可靠和切实可行的。     

基于拉盖尔函数的卫星姿态预测控制方法

针对卫星在空间站中进行绕飞检测时的姿态控制问题，考虑卫星的姿态轴需要躲避禁飞区域并指向期望位置，提出了一种基于拉盖尔函数的模型预测控制方法，实现了对卫星姿态轴的控制。在模型预测控制方法的基础上，通过拉盖尔函数，将优化多个控制输入转换为优化少数的拉盖尔系数，建立了拉盖尔模型预测的控制策略，改善了传统的模型预测控制方法计算效率差的问题，减少了优化时间。采用卫星在空间站中绕飞的模型进行数值仿真验证，结果表明该方法能够使卫星的姿态轴躲避禁飞区并到达指定位置。与传统方法相比，这种基于拉盖尔函数的模型预测控制策略能够提高优化效率，减少计算时间。     

一类基于四面体组合单元的模块化构架式可展开天线机构

针对现有基于四面体单元的构架式天线机构结构复杂、收拢率低、运动副数量多等问题，基于3RR-3RRR四面体组合单元和基于3RR-3URU四面体对称组合单元分别提出了两种新型模块化可展结构。以3个组合单元组成的模块化结构为分析对象，首先，详细介绍了模块化结构的组成及虎克铰轴线布置，并利用组合单元本身的自由度数目及性质，采用拆杆-等效-复原的思想，应用螺旋理论和G-K公式分别对提出的两种模块化结构进行了自由度分析，得到了自由度数目及性质。其次，应用Adams动力学仿真软件对两种模块化结构进行运动仿真，仿真结果验证了自由度分析的正确性。以完全展开和完全收拢时机构所占的空间体积比值表征该机构的收拢率，计算现有基于四面体单元的非模块化机构与提出的模块化机构的收拢率。最后，对比分析非模块化机构与模块化机构的自由度数目、运动副数目及收拢率。分析结果表明，基于3RR-3URU四面体对称组合单元的模块化结构既能实现较大收拢率，自由度及运动副数目也相对减少，且组成大型天线时杆件类型较少。研究结果为该类模块化构架式可展天线结构的设计与分析提供一定理论依据。     

M数缩尺法旋翼颤振动力相似模型设计

本文以延-2复合材料桨叶旋翼为例,用M数缩尺法尝试设计了缩尺比为1/5的颤振相似模型。设计从旋翼颤振微分方程开始,应用π定理得出10个独立相似准则数,列出各有关物理量缩尺因子后进行模型结构设计,从而得出了若干有益的结论。