地空靶场实时GPS伪距差分测量系统的应用研究

地空靶场实时GPS差分高精度测量系统是当代飞机飞行试验中解决火控系统标校、测控系统校飞或导弹武器系统精度试验等问题的有效手段,是地空靶场测控系统的重要组成部分。本文基于伪距观测量的GPS实时差分定位的原理以及对数学模型的分析,论述了将GPS实时定位技术应用于地空靶场中机载或弹载导航系统的实现方法。文中详细的规划了基准站...     

改进谢别德插值方法在地磁图构建中的应用

构建地磁图是地磁/惯性组合导航研究的一项重要内容,为了提高地磁导航中地磁基准图的精度,本文分析研究了改进谢别德插值算法,简要概述了数字地磁图的构建原则,并将改进谢别德插值算法应用到地磁图构建中.通过实验验证,发现该方法与距离加权反比插值算法、克里格插值算法相比,具有较好的插值效果.由此,初步判定改进谢别德插值算法在地磁...     

一种融合卡尔曼滤波的改进时空上下文跟踪算法

针对时空上下文跟踪算法对快速运动和遭受严重遮挡目标的跟踪精度下降问题,提出一种融合卡尔曼滤波的改进时空上下文跟踪算法。首先人工标记目标所在的矩形区域,然后利用改进的时空上下文算法对目标进行稳定跟踪,在跟踪过程中,基于连续两帧图像灰度的欧氏距离判定目标跟踪状态,当判定目标遭受严重遮挡时,利用卡尔曼滤波进行预测估计。算法对噪声有一定的容忍度,通过降低噪声对跟踪过程的影响,能够得到更优的目标区域。仿真实验结果表明:本文算法适用于不同光照强度下高速、高机动目标的稳定跟踪,并且对目标的尺度变化和短时严重遮挡具有鲁棒性。算法帧平均耗时为34.07ms;帧几何中心平均误差为5.43pixel,比时空上下文算法减少70.2%;目标轮廓面积平均误差为13.08%,比时空上下文算法减少52.7%。     

Fuzzy压缩映象不动点定理

本文将Fuuzy压缩原理进行了推广，首次通过引入一个Fuzzy ε上半连续函数和Fuzzy链空间成功的证明了Fuzzy数值函数的不动点定理。     

度量空间X与H(X)空间的连续映射

度量空间是用距离来定义拓扑结构的特殊拓扑空间，度量空间的完备性是度量空间的一个独有的性质．在完备度量空间上建立分形空间H(X)，如果函数在完备度量空间上连续，则函数在分形空间H(X)空间上连续。由局部基的覆盖来刻划紧空间，用H(X)表示X中的全体非空紧集构成的集族．在此集族中定义豪斯道夫距离，连续映射的定理在分形空间成立。     

A new grid deformation technology with high quality and robustness based on quaternion

Quality and robustness of grid deformation is of the most importance in the field of aircraft design, and grid in high quality is essential for improving the precision of numerical simulation. In order to maintain the orthogonality of deformed grid, the displacement of grid points is divided into rotational and translational parts in this paper, and inverse distance weighted interpolation is used to transfer the changing location from boundary grid to the spatial grid. Moreover, the deformation of rotational part is implemented in combination with the exponential space mapping that improves the certainty and stability of quaternion interpolation. Furthermore, the new grid deformation technique named ‘‘layering blend deformation' is built based on the basic quaternion technique, which combines the layering arithmetic with transfinite interpolation(TFI) technique. Then the proposed technique is applied in the movement of airfoil, parametric modeling, and the deformation of complex configuration, in which the robustness of grid quality is tested. The results show that the new method has the capacity to deal with the problems with large deformation, and the ‘‘layering blend deformation' improves the efficiency and quality of the basic quaternion deformation method significantly.     

基于N-S方程的加油机对受油机气动干扰研究

空中加受油时,加油机尾流场会对受油机产生复杂的流动干扰。采用基于Navier-Stokes（N-S）方程的CFD方法分析加油机尾流场,并对加油机、受油机之间的气动干扰进行一体化模拟研究;系统地分析加油机不同迎角及双机不同高度差、不同侧向距离、不同前后位置时,受油机的纵向、横航向气动力特性。结果表明：典型状态下,加油机迎...     

从“权力距离”视角解读大学英语口语教学之现状

大学英语口语教学中的一个难题是学生在口语练习过程中的不参与、不配合。文化维度理论的“权力距离”可从文化差异的角度去解读造成师生关系尴尬的原因，从而为改进大学英语口语教学效果提出一些有效的教学建议。     

Guidance laws for attacking defended target

In this paper, two new guidance laws based on differential game theory are proposed and investigated for the attacker in an attacker-defender-target scenario.The conditions for the attacker winning the game are analyzed when the target and defender using the differential game guidance law based on the linear model.The core ideas underlying the two guidance laws are the attacker evading to a critical safe boundary from the defender, and then maintaining a critical miss distance.The guidance law more appropriate for the attacker to win the game differs according to the initial parameters.Unlike other guidance laws, when using the derived guidance laws there is no need to know the target and the defender's control efforts.The results of numerical simulations show that the attacker can evade the defender and hit the target successfully by using the proposed derived guidance laws.     

激光绝对测距中相位信号的数字处理方法综述

随着工业4.0时代的来临，精密测量的技术发展变得越来越重要。绝对距离测量作为精密测量的一个重要组成部分，其测量精度离不开对信号相位信息的分析，而相位信息一般可以通过数字处理方法来获得。本文介绍了激光绝对距离测量中涉及到的相位信号数字处理方法的相关原理及应用。