Multi-disciplinary design optimization with variable complexity modeling for a stratosphere airship

This paper proposes a hybrid architecture based on Multi-disciplinary Design Optimization(MDO) with the Variable Complexity Modeling(VCM) method, to solve the problem of general design optimization for a stratosphere airship. Firstly, MDO based on the Concurrent SubSpace Optimization(CSSO) strategy is improved for handling the subsystem coupling problem in stratosphere airship design which contains aerodynamics, structure, and energy. Secondly, the VCM method based on the surrogate model is presented for reducing the computational complexity in high-fidelity modeling without loss of accuracy. Moreover, the global-to-local optimization strategy is added to the architecture to enhance the process. Finally, the result gives a prominent stratosphere airship general solution that validates the feasibility and efficiency of the optimization architecture. Besides, a sensitivity analysis is conducted to outline the critical impact upon stratosphere airship design.     

Using PoF models to predict system reliability considering failure collaboration

Existing Physics-of-Failure-based (PoF-based) system reliability prediction methods are grounded on the independence assumption, which overlooks the dependency among the compo-nents. In this paper, a new type of dependency, referred to as failure collaboration, is introduced and considered in reliability predictions. A PoF-based model is developed to describe the failure behavior of systems subject to failure collaboration. Based on the developed model, the Bisection-based Reliability Analysis Method (BRAM) is exploited to calculate the system reliabil-ity. The developed methods are applied to predicting the reliability of a Hydraulic Servo Actuator (HSA). The results demonstrate that the developed methods outperform the traditional PoF-based reliability prediction methods when applied to systems subject to failure collaboration.     

敏捷性导弹的双网络逆动态模糊神经网络控制

新疆敏捷性导弹为了获得更高的机动性、敏捷性和好的导引精度，许多采用推力矢量控制方案，本文讨论了一类带推力矢量控制导弹的数学建模，在此基础上提出了一种适用于此类新型导弹的模糊神经网络控制方案，采用双网络逆动态学控制结构，数字仿真表明所提出的控制方案对于系统内参数不确定性和非线性变化具有强的适应性。     

自旋小卫星姿态动力学建模与控制研究

研究探测近地空间自旋稳定小卫星姿态动力学建模与姿态控制问题,探测任务对该卫星姿态控制有着特殊要求。建模中特别考虑了自旋小卫星双侧伸杆扰动对其姿态运动的影响。利用自旋卫星的章动特性,设计了姿态一章动联合控制器,根据星体横向角速度相位和喷气力矩在惯性空间的方位来确定喷气时刻,采取先章动粗控与进动控制,后章动精控的策略。当卫星受空间扰动力矩长期作用产生较大章动角而需调姿进行轨道机动时,可以应用本控制器方便地调整自旋轴的指向。     

空间机器人动力学建模与模型验证

建立带任意节机械臂的空间机器人动力学模型,并验证了模型的正确性．采用Kane方程建立了各体间转铰具有三自由度的空间多体系统的动力学模型,利用投影算子将所建立的模型退化为各节机械臂间具有单自由度转铰连接的空间机器人动力学模型,依据动力学三大基本定理,即动量定理、动量矩定理、动能定理设计了模型验证方案,通过数学仿真验证了所建立模型的正确性．     

基于产品三维模型的工艺几何特征快速建模方法

开展基于产品三维模型的工艺几何特征快速建模的研究,深入分析工艺几何特征建模所依据的各个要素,研究依据这些要素进行快速建模的算法流程并开发实现,从而实现工艺几何特征的快速建模.     

GPS选择可用性(SA)信号采集与建模

 分析了ＧＰＳ测量伪距的各组成部分,设计了一个ＧＰＳ数据实时采集系统,通过定位计算和时钟偏移滤波的方法分离ＳＡ误差信号,经检验指出ＳＡ误差信号基本是零均值的平稳随机过程,对一段时期定点观测到的ＳＡ误差信号进行ＡＲ（１３）的模型辨识,获得大量的模型数据,从时域和频域对模型参数进行分析得到一些有益的结论。     

驾驶员建模精度分析方法的改进及应用

研究了驾驶员建模精度分析方法和提高建模精度的途径。基于驾驶员在环实时仿真结果,识别驾驶员描述函数,按加权最小二乘准则采用复形调优算法识别模型参数。结合两步识别过程,针对现有模型精度公式在最终模型检验上的缺陷,进一步完善了精度评价公式。根据公式提出了基于灵敏度分析的驾驶员模型参数调整方法。应用结果表明：所建立的公式和方法对提高驾驶员模型建模精度效果明显。     

可视化系统建模语言及其在MIS开发中的应用

介绍了VSML(Visual System Modeling Language)的描述内容及其原语定义和行为描述,并对新完善的数据库信息处理功能进行了介绍;接着对完善后的VSML的体系结构及其功能进行了较详细的描述;然后以商业管理采购员订货系统模型作为实例,介绍了VSML的应用,最后对VSML及其进一步的研究工作进行了小结.     

Aspects of Global Magnetospheric Processes

Magnetospheric global modeling is a method to link observations from distant regions via physical laws and has long played a unique and crucial role in space physics. It, different from computer simulations, represents the highest level of abstraction of the physical understanding of the processes that cause observed phenomena. It results in various specific models. While it appears in the form of cartoons, it is based on and has to be qualitatively consistent with physical laws. With the advancement of computer simulations, clues to the connection between physical laws and observation can be perceived much more easily than as ever before. However, computer simulation results are highly dependent on the used boundary conditions and numerical methods which may or may not represent the reality, even if the initial conditions are properly set. Therefore, simulations can easily mislead the investigations. Furthermore, a simulation result needs to be examined using diagnostic tools, such as field line tracing and streamline tracing programs. There are uncertainties in these diagnostic methods. The errors can be very large in certain areas under certain conditions. For example, a small error may link two different field lines or stream lines. The interpretations of the simulation results can be misled by these errors. The knowledge of global modeling can be useful in identifying the inconsistencies in the simulations and the flaws in the theoretical interpretation from the simulations. This review-tutorial article outlines the principles of the global modeling and discusses the successes and flaws of several global models.