小波分析在雷达信号处理中的应用展望

小波分析在雷达信号处理中的应用研究,已成为近些年来信号处理学科的热点之一。介绍了小波分析的发展历史、研究现状,阐明了小波分析的基本概念,比较了各种小波处理方法的特点,详细讨论了小波在雷达信号处理中的诸多应用,指出了有待解决的各种问题,对小波分析在雷达信号处理中的应用提出了展望。     

水面舰艇编队系统对空作战能力研究

根据现代防空系统的特点,提出了水面舰艇编队区域防空系统效能评价的指标体系,分析了指标的相关因素,运用指数法建立了防空系统效能分指标(预警探测能力指数、拦截打击能力指数、指挥控制能力指数、电子战能力指数)以及效能综合指标的求取模型.     

Thermal and combustion behavior of Al-MnO2 nanothermite with poly(vinylidene fluoride -co- hexafluoropropylene) energetic binder

Fluoropolymers get increasing attention in energetic materials application due to the high fluorine content. To explore the effect of poly(vinylidene fluoride-co-hexafluoropropylene) (P(VDF-HFP)) on Al/MnO2 nanothermite, the samples with different contents are prepared and characterized by SEM, TG-DSC, XRD, and their ignition and combustion behavior are tested and recorded. The results show that P(VDF-HFP) as an energetic binder can combine the nanothermite components together, even exist in the gaps. The integrity of energetic materials has been improved. Thermal analysis shows that the addition of P(VDF-HFP) greatly changes the thermal reaction processes, and the exothermic peaks appear early, but the utilization of fuel and oxidizer is not efficient from the XRD results. Furthermore, the appropriate addition of P(VDF-HFP) can directly reduce the ignition energy threshold and increase the combustion time, which is necessary for the potential ignition charge application. The possible reasons for above phenomena are discussed and analyzed. This research provides a reference for improvement of thermite-based ignition charge formulation.     

多传感器信息融合理论在无人机相对导航中的应用

为提升无人机的作战效能和作战指标,提升无人机的相对导航精度和导航系统可靠性,以无人机编队的相对导航系统为研究背景,基于容积卡尔曼滤波算法和信息滤波算法,研究容积信息滤波算法。此外,还采用多传感器信息融合理论,利用分布式信息融合结构构建了无人机相对导航滤波器,对来自惯导、视觉和卫星的信息进行融合,获取无人机间的相对位置、速度和姿态信息。该方法提升了无人机相对导航的导航精度、导航可靠性和滤波稳定性,容积信息滤波算法的应用避免了传统滤波算法在高维系统中出现的数值不稳定以及精度降低等问题。数学仿真结果表明,该方法提高了无人机编队之间相对导航的精度和可靠性,证明了算法的有效性。     

二维非线性正交各向异性材料的瞬态热传导反问题数值方法

针对正交各向异性材料的二维非线性热传导反问题,采用顺序函数法进行表面热流辨识问题的研究。在求解反问题时,采用有限体积法、牛顿-拉夫逊法并引入未来时间步的概念。在每个时间步内,将待辨识热流视为非线性方程组的未知量,通过一个迭代过程进行求解。算例的研究表明,热流辨识结果与真实热流相近,从而证明了本方法在辨识二维非线性热传导反问题时是准确、稳定、有效的。     

坦克稳定器的自抗扰控制算法

为解决坦克稳定器中存在的传动间隙、干摩擦等强非线性问题,提高系统的鲁棒性,基于自抗扰控制器(ADRC)原理,提出了适用于坦克稳定器的自抗扰控制器,并进行了计算机仿真和试验验证。证明了自抗扰控制算法在坦克稳定器设计中的可行性。     

基于模糊推理的目标对潜发现问题研究

基于模糊推理基本思想,针对潜艇水下收集目标信息的特点,在目标对潜艇威胁信息存在不确定性因素的基础上,建立了判断潜艇被发现与否的指标体系,应用模糊推理方法建立了判断规则,并给出了推导过程和实现方式,在把模糊推理方法应用于潜艇威胁判断模型的研究上做了初步尝试。     

Experimental investigation on anti-penetration performance of polyurea-coated ASTM1045 steel plate subjected to projectile impact

In this study, the anti-penetration performance of polyurea/ASTM1405-steel composite plate subjected to high velocity projectile was analyzed. Two kinds of modified polyurea material (AMMT-053 and AMMT-055) were selected and a ballistic impact testing system including speed measuring target system and high-speed camera was designed. This experiment was conducted with a rifle and 5.8 mm projectile to explore the effects by the polyurea coating thickness, the polyurea coating position and the glass-fiber cloth on the anti-penetration performance of polyurea/ASTM1405-steel composite plate. The result showed that the effects of polyurea coating position were different between two types of polyurea, and that the effects of glass-fiber position were disparate between two types of polyurea as well. For AMMT-053 polyurea material, it was better to be on front face than on rear face; whereas for AMMT-055 pol-yurea, it was better to be on rear surface although the difference was very subtle. Additionally, formulas had been given to describe the relationship between the effectiveness of polyurea and the thickness of polyurea coating. In general, AMMT-055 had better anti-penetration performance than AMMT-053. Furthermore, five typical damage modes including self-healing, crack, local bulge, spallation and local fragmentation were defined and the failure mechanism was analyzed with the results of SHPB test. Additionally, the bonding strength played an important role in the anti-penetration performance of polyurea/steel composite plate.     

Inventory competition with yield reliability improvement

This article studies the inventory competition under yield uncertainty. Two firms with random yield compete for substitutable demand: If one firm suffers a stockout, which can be caused by yield failure, its unsatisfied customers may switch to its competitor. We first study the case in which two competing firms decide order quantities based on the exogenous reliability levels. The results from the traditional inventory competition are generalized to the case with yield uncertainty and we find that quantity and reliability can be complementary instruments in the competition. Furthermore, we allow the firms to endogenously improve their yield reliability before competing in quantity. We show that the reliability game is submodular under some assumptions. The results indicate that the competition in quantity can discourage the reliability improvement. With an extensive numerical study, we also demonstrate the robustness of our analytical results in more general settings. © 2015 Wiley Periodicals, Inc. Naval Research Logistics 62: 107–126, 2015     

空间应用载荷的天地端到端IP隧道协议通信架构设计

在地面运控子网和载荷信息网中设计IPsec、GRE或RFC2003三种IP隧道协议,通过平台信息网和天地测控网,封装的用户数据包能在天地通信链路中路由,以支持在轨载荷和地面运控终端之间端到端的灵活通信。设计支持IP隧道协议通信的天地一体化信息网络架构,给出各级路由器的设置和网段IP地址分配,计算和分析出三种IP隧道协议的通信效率与实时性。分析结果表明,采用IP隧道协议对改变传统地面运控模式、提高运控效率具有重要意义。