基于子阵结构的相控阵MIMO雷达分辨能力分析

在阵元总数一定的情况下,不同的子阵划分方式和布阵间距对不同子阵发射正交波形,子阵内发射相干波形的相控阵-MIMO雷达系统的分辨力的影响,首先通过相控阵-MIMO雷达的信号模型推导出其广义模糊函数,然后以此分析子阵结构对距离、多普勒、方位三维分辨力的影响。仿真结果表明,在阵元总数一定的情况下,子阵越多,系统距离分辨力越高,子阵越大,多普勒分辨力越高,子阵间距满足一定条件才能有较好的系统分辨力。这些结论对相控阵-MIMO雷达子阵结构设计具有指导意义。     

Parallel machine scheduling with batch deliveries to minimize total flow time and delivery cost

Motivated by the flow of products in the iron and steel industry, we study an identical and parallel machine scheduling problem with batch deliveries, where jobs finished on the parallel machines are delivered to customers in batches. Each delivery batch has a capacity and incurs a cost. The objective is to find a coordinated production and delivery schedule that minimizes the total flow time of jobs plus the total delivery cost. This problem is an extension of the problem considered by Hall and Potts, Ann Oper Res 135 (2005) 41–64, who studied a two‐machine problem with an unbounded number of transporters and unbounded delivery capacity. We first provide a dynamic programming algorithm to solve a special case with a given job assignment to the machines. A heuristic algorithm is then presented for the general problem, and its worst‐case performance ratio is analyzed. The computational results show that the heuristic algorithm can generate near‐optimal solutions. Finally, we offer a fully polynomial‐time approximation scheme for a fixed number of machines. © 2016 Wiley Periodicals, Inc. Naval Research Logistics 63: 492–502, 2016     

利用实际飞行数据插值的INS/GNSS组合导航仿真轨迹发生器

针对INS/GNSS组合导航仿真中捷联惯导系统陀螺、加速度计信号高精度模拟问题,提出基于实际飞行数据插值的动态轨迹解析生成仿真算法。对转换到地心惯性坐标系中的载体姿态、位置和重力场数据进行关于时间的样条函数插值,得到载体坐标系下陀螺角速率、角增量以及加速度计比力积分增量的高精度分段解析表达式。使生成的陀螺、加速度计信号符合载体运动学和动力学特性,反映杆臂效应影响,同时与经事后处理的实测GNSS伪距、伪距率等数据特征保持一致。提出四元数约束插值算法,其可满足四元数解析插值时范数为1的约束限制条件。基于某实际无人机飞行数据,验证了所提算法的有效性,其完全满足组合导航动态仿真精度要求。该算法也适用于其他高精度高动态导航系统和刚体运动控制仿真中的角运动、线运动传感器信号模拟。     

The mechanical performance and a rate-dependent constitutive model for Al3Ti compound

The Al₃Ti compound has potential application in the high temperature structure materials due to its low density, high strength and stiffness. The mechanical behaviors of the material under different loading rates were studied using compression tests. The results indicate that Al₃Ti is a typical brittle material and its compressive strength is dependent on the strain rate. Therefore, a series of rate-dependent constitutive equations are needed to describe its mechanical behaviors accurately. However, it is still short of professional research on the material model for Al₃Ti. In this study, the material model was developed on the basis of JH-2 constitutive equations using the experimental data. The model was then applied in simulating the impact process of Ti/Al₃Ti metal-intermetallic laminate composites so as to validate the established model. Good agreement between simulation and experiment results shows the constitutive model predict the material responses under high rate and large deformation accurately. This work provides more support for the theoretical and numerical research on the intermetallic.     

中子增殖研究

导出了一个新的中子增殖公式,公式简明,计算量小.经与传统的增殖公式进行比较,后者由于未考虑缓发中子效应,只能用于定性分析.新导出的中子增殖公式较精确地描述了中子的增殖过程,可用于定量计算与分析.     

基于PCI总线图像采集卡的数字视频监控系统

介绍了一种基于PCI总线图像采集卡的数字视频监控系统 ,给出了系统结构和实现方法。对制式转换和多线程等相关技术进行了详细介绍 ,给出了完整的框图 ,并附有实用程序。     

基于软件的多路PWM式D/A转换技术

主要介绍了一种利用单片机定时器产生中断,操作Ｉ／Ｏ口线输出多路ＰＷＭ信号,通过接口转换电路输出模拟量的思想,说明了应用单片机定时器缓冲区的数据设置,并给出了中断服务例程。     

战术互联网中的视频传输技术

介绍了战术互联网,阐述了视频传输技术的简单原理和基本特点,分析了视频传输在战术互联网中的几种传输技术。     

基于模糊时间序列的时变动态系统模糊建模

要想建立结构不确定、参数时变的动态系统的模型是很困难的。改进了Song Chisson的模糊时间序列方法,并成功应用于时变动态系统的辨识与建模和自适应控制。仿真结果表明该方法计算量小,实时性好,能很快地跟踪系统的变化。     

MS860动态测姿试验精度分析

为了评估动态MS860型GPS姿态测量性能,将其安装在某船上进行系统测试.采用动态滤波的方法采集MS860姿态信息,同时同步采集某型平台罗经的数据.在此基础上,用误差统计方法评估姿态测量系统的精度性能.结果表明GPS姿态测量系统可以满足舰船姿态测量的需要,其航向的测量精度优于平台罗经系统.