Precision tracking algorithms of civil aircraft by radar information

The problem of radar tracking of air traffic management by multiple model algorithms is discussed. Three types of multiple model algorithms are described. The various types of hypotheses combining algorithms are discussed. The simulation results are presented.     

Spectral Analysis of Orbits via Discrete Fourier Transforms

We give some simple and direct algorithms for deriving the Fourier series which describe the quasi-periodic motion of regular orbits from numerical integrations of those orbits. The algorithms rely entirely on discrete Fourier transforms. We calibrate the algorithms by applying them to some orbits which were studied earlier using the NAFF method. The new algorithms reproduce the test orbits accurately, satisfy constraints which are consequences of Hamiltonian theory, and are faster. We discuss the rate at which the Fourier series converge, and practical limits on the degree of accuracy that can reasonably be achieved.     

New track correlation algorithms in a multisensor data fusion system

In order to resolve the problem of track-to-track association in a distributed multisensor situation, this paper presents independent and dependent sequential track correlation algorithms based on Singer's and Bar-Shalom's algorithms. Based on sequential track correlation algorithm, the restricted and attenuation memory track correlation algorithms and sequential classic assignment rules are proposed. In this paper, these algorithms are described in detail. Then, the track correlation mass and multivalency processing methods are discussed as well. Finally, simulations are designed to compare the correlation performance of these algorithms with that of Singer's and Bar-Shalom's algorithms. The simulation results show that the performance of these algorithms proposed here is much better than that of the classical methods under the environments of dense targets, interfering, noise, track cross, and so on. Under the above situations, their correct correlation ratio is improved about 69 percent over the classical methods     

由后验概率密度递推导出的地形轮廓匹配定位算法

 飞行器一边飞行,一边不断测出下方地面的海拔高度或飞行器与地面间的高程差,和已知的基准地形图比较,从而确定飞行器的位置,这就是地形轮廓匹配定位问题。本文给出了根据测高数据进行后验概率密度递推的基本公式,由此简化得到的几个具体算法,经计算机在实际地形图上仿真表明,具有递推执行,截获概率和定位精度较高,可用于任意飞行航迹和不等间隔测高,可对付较严重的随机扰动、航速误差和航向偏差等特点。     

Fast Algorithms for Time Domain Broadband Adaptive Array Processing

Recursive algorithms are presented for time domain, broadband, adaptive beamforming. The algorithms are rapidly converging and can be computationally efficient for a certain range of array processor parameters. The algorithms are presented for two forms of array processor. One form is a Frost-type structure in which explicit constraints are required for defining the array-look direction and also to control the sensitivity of the array processor to implementation errors. The other form is a partitioned array processor in which constraints are built into the processor and the adaptive weight control algorithm is therefore unconstrained. The two processors presented are both element-space processors but the algorithms can be applied also to beam-space processors.     

冲击响应谱（SRS）分析数字化方法探讨

本文介绍了求单自由度二阶系统冲击响应谱（ＳＲＳ）的几种常用的数字化分析方法：直接积分法；快速富氏变换（ＦＦＴ）法；递推法；数字滤波器方法；改进的数字滤波器方法。并比较了它们的优缺点。     

Implicit Adaptive Control for a Class of MIMO Systems

Two implicit model reference adaptive control algorithms for multi-input multi-output systems are developed. These algorithms do not require either satisfaction of the perfect model following conditions or explicit parameter identification. The first algorithm ensures asymptotic stability of the output error provided that the output stabilized plant transfer matrix is strictly positive real. The second algorithm guarantees a bounded error under less restrictive conditions. The algorithms are applied to the lateral axis of an F-8 aircraft.     

应用SVM的发动机故障诊断若干问题研究

支持向量机能够克服一般神经网络容易出现的过学习和泛化能力低等不足。提出一种基于支持向量机的航空发动机气路部件故障诊断方法,讨论了支持向量机的核函数选择和参数确定问题,并对"块算法"进行了分析。仿真实验表明,设计的正则化参数和核参数合理,故障分类器具有良好的分类准确性和泛化性能,可以对发动机气路部件的典型故障进行正确诊断。     

基于酉变换的约束优化均衡算法

基于李道本等人提出的代价函数，在特定的约束条件下，利用酉变换方法，提出了两个约束化均衡算法。这两种均衡算法是传统的直接梯度算法和共轭梯度算法的改进方法。这两种约束算法是在Householder变换下或GiVen平面旋转变换下获得的，它们完全不同于前人的各种线性约来自适应算法，这两种算法的计算复杂度是可以接受的。计算机仿真结果验证了这两种变换域算法的性能。     

快速定位定向系统设计及车载实验研究

定位定向系统是能为载体提供精确地理位置坐标、指北方向和姿态角的导航系统,通常用于舰船、飞机、车辆等功能平台,为平台上的设备提供准确的位置和姿态参考信息.本文针对车载平台机动性高的特点,设计能够实现运动中对准的快速定位定向系统,开展捷联惯导数字递推算法、航位推算、多源信息组合导航、动基座对准算法、系统免标定、误差补偿等算法和技术研究.最后,开展静态对准、静态导航和动态车载实验研究.实验结果表明,动态对准时间小于5min,对准姿态精度小于1mil,方位保持精度小于1mil/2h,横滚角、俯仰角保持精度小于0.5mil/2h,里程计/惯导组合水平定位精度小于0.15％D,卫星/惯导组合水平定位精度小于10m.     

Complexity analysis of wavelet signal decomposition andreconstruction

We give certain sequential and parallel algorithms and their computational analysis for signal decomposition and reconstruction based on wavelets. The signal decomposition (respectively, reconstruction) process is separated into two stages: the first is the preprocessing stage where certain constants are computed for implementation to prepare for the second stage in which signal decomposition (respectively, reconstruction) is performed. In the decomposition (respectively, reconstruction) stage, the input signal is transformed via different methods to compute the output signal without changing the setup initialized in the preprocessing stage. We describe certain sequential algorithms for both the preprocessing and the decomposition (respectively, reconstruction) stages, and parallel algorithms for the latter. The algorithms are finally illustrated for compactly supported spline-wavelets and are analyzed in detail in terms of the required arithmetic operations     

Routing in networks of intersatellite links

How to characterize and implement point-to-point (i.e., unicast) routing algorithms is discussed. The characteristics of routing algorithms are first described as well as the specificities of routing in constellations of nongeostationary (NGO) satellites equipped with intersatellite links (ISLs). Then, some of the candidate algorithms displaying the characteristics identified before are simulated and evaluated for different constellations. From the simulation results, it appears that (1) from a routing perspective, constellations are not similar to terrestrial networks, and (2) the constellation geometry has a significant impact on the routing performance.     

两种初始对准算法的比较研究

初始对准的精度作为影响惯性导航系统精度的核心因素,一直受到广泛的研究。传统初始对准算法存在对扰动敏感、对准时间长、需要小失准角假设等诸多缺陷。针对传统算法的不足,有学者最近提出了一些思路新颖的初始对准算法,如优化对准算法和基于频域分离算子的初始对准算法。本文对比研究了这两种初始对准算法的基本原理,通过摇摆台实测数据对两种算法进行了验证,对工程应用具有一定的参考价值。     

M-ary sequential hypothesis tests for automatic targetrecognition

Several forms of sequential hypothesis testing algorithms are described and their performance as classification algorithms for automatic target recognition is evaluated and compared. Several forms of parameteric algorithms, as well as a sequential form of a useful nonparametric algorithm are considered. The primary focus is the design of algorithms for automatic target recognition that produce maximally reliable decisions while requiring, on the average, a minimum number of backscatter measurements. The tradeoffs between the average number of required measurements and the error performance of the resulting algorithms are compared by means of Monte-Carlo simulation studies     

传递对准姿态匹配的优化算法

 推导了4种传递对准姿态匹配算法,分析了这4种姿态匹配算法的优缺点,证明并验证了其中的“最优姿态匹配法”在姿态匹配算法中的最优性。首先介绍了传统的“姿态角匹配法”及其改进算法,即“姿态矩阵匹配法”,接着引入了量测失准角的概念,经过理论推导,提出了利用量测失准角进行传递对准姿态匹配的“量测失准角匹配法”。上述3种姿态匹配算法都是在子惯导安装角是小量的条件下推导而获得的,只能适用于安装角是小量的条件,具有一定的局限性。基于此,对“量测失准角匹配法”进行了完善,推导出了一种可在多挂点下使用的现代姿态匹配算法——最优姿态匹配法。从理论上证明了4种姿态匹配算法的相互关系。最后,采用“速度＋姿态”匹配方案进行的传递对准仿真结果表明：4种姿态匹配算法具有相同的估计精度;推导的“最优姿态匹配法”在保证精度的同时,可应用于子惯导安装角是任意角度的情况,具有更广的应用范围。     

捷联惯性导航传统比力积分算法与对偶四元数算法的比较研究

捷联惯性导航速度更新算法中,将载体坐标系中的比力积分增量变换到导航参考坐标系中,载体姿态变化的影响通常采用一阶近似模型进行计算。本文分析了包括角振动和加速运动的动态运动下一阶近似模型的局限,在典型角振动及加速运动条件下对忽略姿态变化二阶项造成的速度更新误差进行了理论分析。通过比较,揭示了对偶四元数比力积分算法精度高于传统比力积分算法的原因,即和传统比力积分算法相比,对偶四元数比力积分算法等价于考虑了载体姿态变化影响的二阶项。通过典型角振动及加速运动条件下传统捷联惯性导航算法和对偶四元数导航算法的仿真比较,对理论分析结果进行了验证。     

基于Nash-Pareto策略的两种改进算法及其应用

针对多目标、多设计变量的优化问题,提出了两种优化的新算法:一种是将多目标问题转化为单目标时,对目标权重的确定提出了新的途径;另一种是直接对多目标问题进行优化,并对Pareto遗传优化技术作了改进,以得到均匀分布的Pareto最优解集.两种新算法都是建立在Nash的系统分解与Pareto遗传算法的基础上,因此称这类算法为Nash-Pareto策略.借助于这类算法,文中以跨声速压气机双圆弧类叶型的气动优化为例,给出了气动优化的全过程.数值优化的实验表明所给出的改进算法是可行的、有效的.     

具有确定弧数最长路的算法

给出了寻求强连通赋权有向图中从一顶点到任意顶点间具有确定弧数的最长路 (最短路 )和最长初等路 (最短初等路 )的算法 ,并对算法的有效性进行了讨论。该算法对扩展 Karp和Cohen的结果——强连通赋权图中最小平均权的算法和线性离散事件系统的闭环系统矩阵在极大代数意义下的特征值的算法 ,具有实际意义     

基于遗传算法的大型空间结构模型降阶

 采用遗传算法求解大型空间结构的模型降阶问题。给出了模型降阶的数学表示和所用遗传算法的有效形式，即编码方式、适值方式、交叉方式和变异方式等。仿真实例说明，遗传算法优于标准内平衡法和Hopfield神经网络方法。     

基本曲线的斜线插补生成算法

根据斜线插补算法的基本原理推导出了直线、圆及椭圆等基本曲线的生成算法,其主要结果均以形式简单,实用性强的递推公式得出。