四足机动平台的静步态规划研究

基于仿生学原理进行了四足机动平台的腿部结构设计,分析了负载因子、周期、步距等步态设计参数对静步态稳定性的影响,提出了平地直行条件下从起步到稳定行走的步态调整方式,并对静步态行走全过程的稳定裕度进行了求解。计算结果表明：所规划的行走步态能达到静步态运动稳定性要求。     

先张预应力BFRP筋混凝土梁受弯性能试验研究

玄武岩纤维筋是一种新型复合材料,具有轻质、高强、非磁性、耐高温、耐酸碱等多重优点.完成了直径为10 mm的BFRP筋基本力学性能测试.进行了3根先张有粘结预应力BFRP筋混凝土梁,1根非预应力BFRP筋混凝土梁的受弯性能对比试验,分析了试验梁受力过程及破坏形态、平截面假定情况、特征荷载值、荷载--挠度关系、裂缝发展情况...     

水面舰艇攻势防御的效能评估及优势论证

进攻是最好的防守。针对水面舰艇攻势防御问题,对水面舰艇攻势防御的概念及使用前提进行了讨论,通过与守势防御的比较,从理论上对攻势防御的优势进行了论证。最后,根据论证结果、数据仿真及作战实际,给出了攻势防御的使用原则。     

面向空间应用的GaN功率器件及其辐射效应

研究氮化镓(GaN)功率器件及其辐射效应对于解决空间应用需求、促进新一代航天器建设具有重大意义。介绍了GaN功率器件的主要结构及工作原理,综述了近年来国内外在GaN功率器件的总剂量效应和单粒子效应两方面的研究进展,并对辐射效应在GaN功率器件中造成的退化和损伤机制进行分析与讨论。研究结果显示：GaN功率器件具有较强的抗总剂量能力,但是抗单粒子能力较弱,易发生漏电和单粒子烧毁,且烧毁点多发生在栅极边缘的漏侧。对GaN功率器件辐照损伤机理的研究缺乏权威理论,有待进一步探索,为其空间应用提供理论支撑。目前,平面结构的GaN功率器件是主流的技术方案,单片集成及高频小型化是GaN功率器件未来发展的方向。     

Effect of metal powders on explosion of fuel-air explosives with delayed secondary igniters

In order to improve the energy level of fuel air explosive(FAE) with delayed secondary igniters, high energetic metal powders were added to liquid fuels mainly composed of ether and isopropyl nitrate. Metal powders' explosive properties and reaction mechanisms in FAE were studied by high-speed video, pressure test system, and infrared thermal imager. The results show that compared with pure liquid fuels, the shock wave overpressure, maximum surface fireball temperature and high temperature duration of the mixture were significantly increased after adding high energetic metal powder. The overpressure values of the liquid-solid mixture at all measuring points were higher than that of the pure liquid fuels. And the maximum temperature of the fireball was up to 1700 ℃, which was higher than that of the pure liquid fuels. After replacing 30％of aluminum powder with boron or magnesium hydride, the shock wave pressure of the mixture was further increased. The high heat of combustion of boron and the hydrogen released by magnesium hydride could effectively increase the blast effect of the mixture. The improvement of the explosion performance of boron was better than magnesium hydride. It shows that adding high energetic metal powder to liquid fuels can effectively improve the explosion performance of FAE.     

Research on fuze microswitch based on corona discharge effect

Abnormal voltages such as electrostatic, constant current, and strong electromagnetic signals can erro-neously trigger operation of MEMS pyrotechnics and control systems in a fuze, which may result in casualties. This study designs a solid-state micro-scale switch by combining the corona gas discharge theory of asymmetric electric fields and Peek's Law. The MEMS switch can be transferred from "off" to"on" through the gas breakdown between the corona electrodes. In the model, one of the two electrodes is spherical and the other flat, so a non-uniform electric field is formed around the electrodes. The theoretical work is as follows. First, the relation among the radius of curvature of the spherical electrode, the discharge gap, and the air breakdown voltage is obtained; to meet the low voltage (30-60 V) required to drive the MEMS switch, the radius of curvature of the spherical electrode needs to be 10-50 μm and the discharge gap between the two electrodes needs to be 9-11 μm. Second, the optimal ratio ε is introduced to parameterize the model. Finally, the corona discharge structural parameters are determined by comparing the theoretical and electric field simulation results. The switch is then fabricated via MEMS processing. A hardware test platform is built and the performing chip tested. It is found that when the electrode gap is 9 μm, the electrostatic voltage is at least 37.3 V, with an error of 2.6% between the actual and theoretical air breakdown voltages. When the electrode gap is 11 μm, the electrostatic voltage is at least 42.3 V, with an error of 10.5% between the actual and theoretical air breakdown voltages. Both cases meet the design requirements.     

Visual-attention gabor filter based online multi-armored target tracking

The multi-armored target tracking (MATT) plays a crucial role in coordinated tracking and strike. The occlusion and insertion among targets and target scale variation is the key problems in MATT. Most state-of-the-art multi-object tracking (MOT) works adopt the tracking-by-detection strategy, which rely on compute-intensive sliding window or anchoring scheme in detection module and neglect the target scale variation in tracking module. In this work, we proposed a more efficient and effective spatial-temporal attention scheme to track multi-armored target in the ground battlefield. By simulating the structure of the retina, a novel visual-attention Gabor filter branch is proposed to enhance detection. By introducing temporal information, some online learned target-specific Convolutional Neural Networks (CNNs) are adopted to address occlusion. More importantly, we built a MOT dataset for armored targets, called Armored Target Tracking dataset (ATTD), based on which several comparable experiments with state-of-the-art methods are conducted. Experimental results show that the proposed method achieves outstanding tracking performance and meets the actual application requirements.     

舰空导弹防空体系分析

从舰空导弹武器作战任务的需求出发,分析了舰空导弹体系的组成,给出了评估体系优劣的指标。简要回顾了国外舰空导弹武器的发展,阐述了美、俄、英等国家舰空导弹体系的构成,并展望了舰空导弹发展趋势。     

数字高程模型数据小波压缩算法

针对海量DEM数据的存储和传输的问题,设计出一种高效的DEM数据的小波压缩算法。基于提升理论提出了一种包含自由变量t的紧支撑小波构造方法;通过选取合适的小波滤波器系数,基于提升的整数小波变换只需要整数加法、整数乘法和移位实现,运算速度快,便于硬件实现;选取参数t=1的整数9-7小波变换,其运算量接近整数5-3小波,但DEM数据压缩质量接近浮点的CDF9-7小波。实验证明该压缩算法对DEM数据有极佳的压缩效果,在保持地形形状和起伏特征的前提下,DEM数据可以压缩4096倍,PSNR>34DB。     

基于二进小波变换的噪声图像自适应增强新算法

针对图像增强算法通常会放大原图像中噪声分量的问题,提出了一种基于二进小波变换的图像增强新算法。该算法充分利用了二进小波变换的平移不变性和各尺度上小波系数间的相关性,有效改善了增强过程中噪声放大和边缘失真问题。此外,算法具有高度的自适应能力,适用性更强。实验结果表明,与目前已有的各类多尺度图像增强算法相比,该算法在抑制噪声和凸显图像特征两方面均有明显改进。