利用圆柱阵的空中目标测距算法研究

为提高三维空间目标的测距精度,提出利用圆柱阵的近似时延测距算法.首先根据圆柱阵中部分阵元具有不同时延表达式的特点,推导出空间目标的测距公式;然后在测向结果的基础上,仿真分析该算法的测距性能;最后利用外场实验对算法的性能进行验证.仿真及实验结果表明:利用圆柱阵的近似时延测距算法对距离估计的相对误差随信噪比增大快速下降,在...     

m序列在激光测距雷达中的应用

针对激光远程测距中的微弱信号检测,提出了一种基于m序列的激光测距方法,并给出了基于高速数字信号处理器的激光测距雷达数字信号处理系统的实现方案。利用m序列良好的相关特性以及相关检测和相干积累技术,有效地提高了激光测距雷达的性能。还提出了3点插值算法并将其用于目标距离估计,进一步提高激光雷达的测距精度。在外场试验中,得到良好的试验结果。     

群时延对扩频测距系统测距精度的影响

采用Taylor级数展开的方式表征群时延特征,建立了群时延对扩频测距系统测距精度影响的评估模型,推导了测距精度评估参数的数学表达式.利用计算仿真分析了群时延对码跟踪环路输出的相关函数、相关损失、S曲线的影响,为高精度测距系统提供了一种有效的评估手段.     

基于FPGA的脉冲测距机载系统中编译码模块的设计与实现

根据某型飞机分米波仪表着陆系统测距单元的基本工作原理．提出了一种基于FPGA的机载测距编译码模块设计方案。本方案使用一片300万门FPGA实现了由分立元件构成的原模拟系统的基本功能．使测距精度大大提高,并且这种方案具有较强的设计灵活性和可扩展性。经实际测试和仿真证明,本方案可以完全实现设计功能,运行稳定可靠。     

一种基于伪码测距的高度表实现方案

针对高度表测高范围大,测距精度高的要求,文中给出了一种基于伪码测距高度表的实现方案,应用伪码时延的码元整周期数进行粗测距,将收端伪码信号进行锁相提纯及采用差频测相技术对伪码时钟信号相移精确测量以达到精测距.这一方案,在计时时钟频率仅为50MHz的条件下,测高精度优于0.3m,量化误差小于0.2m.     

双向比对技术弹丸空间位置高精度测量方法

将弹丸作为未知目标,测距精度受限,且具有较高的系统实现复杂度;将弹丸作为合作目标,提出了一种基于双向比对技术的弹丸空间位置高精度测量方法,给出了相应的系统设计方案;针对此体制的测距及测速理论和仿真分析结果表明:所提方法能够显著提高弹丸空间位置的测量精度,提高系统工作效能.     

通过数字增益控制提高激光脉冲测距精度

针对激光脉冲测距精度较低的问题,提出了一种利用数字增益控制(DGC)技术提高激光脉冲测距精度的方法。该方法依据获取的回波脉冲信号幅度信息,通过DGC电路实时调整接收系统增益,有效地减少了时刻判别误差对测距精度的影响。试验结果表明:采用此项技术后的激光脉冲测距系统在300m距离范围内具有较高的动态实时测距精度,对于工程应用具有一定的理论参考价值。     

导弹引信高速数字信号处理

本文提出了脉冲多普勒导弹引信的数字信号处理方案，提高了引信的信号处理能力和处理速度。通过高速Ａ／Ｄ采样，采用内插法能获得极高测距精度；利用弹载计算机对目标进行频谱分析和识别；利用制导信息，提高炸点控制精度。     

正交频分复用探测体制研究

提出一种新的无线电引信探测体制一正交频分复用探测体制的设想，介绍了该体制的原理，初步分析了该体制的抗干扰性能和测距性能。通过分析表明所提出的新探测体制利用大量并行的多载波子信道进行目标探测和利用回波信号的时．频相关特性进行信息提取，具有强的抗有源干扰能力，并可获得高精度的距离，速度等信息。     

弹丸落点被动声定位方法

为提高目前炮兵定位以及靶场试验弹丸落点检查精度,提出一种基于五元十字阵的双基阵定位模型.分析五元十字阵中测距、阵元间距对定位精度的影响,介绍利用声传感器阵列的被动声定位方法,利用三角交会法对目标进行定位并仿真分析.仿真结果表明:基于五元十字阵的双基阵比单基阵的测距相对误差小,能够有效提高定位精度,具有较好的工程应用价值.     

Nitrosation and Nitration of Tetraacetyldibenzylhexaazaisowurtzitane

Tetraacetyldibenzylhitane (TADBIW) was subjected to debenzylation by nitrosating with inorganic materials available commercially to synthesize tetraacetyldinitrosohexaazaisowurtzitane (TADNSIW). TADNSIW was purified, and its structure was determined by FTIR, 1H NMR, MS and element analysis. The debenzylation reaction of TADBIW gave quantitative benzaldehyde as a by-product. This indicates that the reaction produces an imine cation as an intermediate. Hexanitrohexaazaisowurtzitane (HNIW) was prepared from unpurified TADNSIW with the yield over 96.0 % and the purity more than 98.0 %. And the mechanism of the reaction from TADNSIW to HNIW is proposed to be oxidation of nitroso and nitration of acetyl on the molecule of TADNSIW, This reaction system involved is simple, and the reaction can complete within a short time and under mild conditions. The product can be easily to separate and the waste disposed readily.     

A Robust Algorithm for Watermarking 2D Vector Maps with Low Shape-Distortions

The technique of watermarking has been introduced into 2D vector maps for many potential applications such as protecting the copyright of important GIS （geographical information system） data and tracing the data source of military maps. In most previous works, although the validity of the map data could be preserved during the embedding procedure, the shape-distortions of the map elements are usually neglected which would tend to degrade the invisibility of the watermarking schemes. A shape-preserving algorithm for watermarking 2D vector maps is presented in this paper. A 1D distance sequence extracted from the original map is adopted as the cover data instead of 2D coordinates. A watermark bit is represented by changing the distributions of the cover data. The embedding procedure induces lower shape-distortions than in former works. Experimental results indicate better invisibility of the proposed scheme, as well as its robustness to certain attacks such as map simplification, interpolation, additive noise and most geometric transforms.     

Open Rule-setting System Applied to Conceptual Design of Engines

Open rule-setting method advanced in this paper concentrates on providing designers of engines with a convenient way to express their design innovations and develop the expected prototypes in the early CAD stage, and constitute effective models for the following analysis process of CAE and CAPP. The problems arisen in the process of conceptual design with the traditional experience-based development method are analyzed. Based on those analyses, open rule-setting method is presented and some associated technical problems are discussed. The functional framework of open rule-setting system was built as software engineering methods. The speciality of the engine product as a kind of complex product and the requirement of the engine product based on its structural particularity to rule-setting system are considered carefully. A demonstration is supplied to illustrate how the open rule-setting method enhances the efficiency and quality of the engine conceptual design.     

Research on Linux Network Device Driver

By analyzing the working principle of Linux network device driver, discussing the Linux network driver structure and its key technologies, the general network driver structure and its design methodologies in Linux system are summarized. Through modifying the network device driver of Linux device driver 3rd version snull, c and improving the COW technology, the Zero-Copy technology in Linux （kernel version 2.6.11 ） is implemented. In the end, the success test tells us that the thorough analysis of network device driver is the foundation of many applications, and it also provides a certain improvement to a lot of real applications, even to military application development.     

Method for Measuring Velocity of Warhead Fragments Based on Photoelectric Detection

For measuring velocity and impacting position of single fragment of warhead, a non-contact measuring method is proposed, in which a six-light-screen array, a position indicator, a multi-channel chronograph and a computer are used.The principle of measurement is described. The key device of the system is a light screen array sensor which consists of six light screens allocated with certain geometrical parameters. When the fragment flies through the light screen array, the time of passing through each of the screens is recorded by the multi-channel chronograph. According to the time data and the geometrical parameters of the array, the velocity vector and the location of the fragment can be calculated immediately. The presented method can be used to locate the fragment and to measure the real velocity on its flying direction. It can also be used to measure the velocity of a fragment swarm after the system is engineered further.     

数码电子雷管中影响点火头性能因素分析

阐述了数码电子雷管中,点火药剂细结晶三硝基间苯二酚铅（LTNR）的制备工艺;从点火药剂的种类、加入黏合剂的质量分数、桥丝直径、点火头的电阻值、防潮漆的蘸涂等方面对点火头性能的影响因素进行了探讨;通过震动试验、并联起爆试验、延期精度检测与考核,试验结果表明：一次性合成的细结晶LTNR是制造数码电子雷管点火头较为理想的点火药剂,按技术要求生产的点火头性能指标能够满足行业标准要求。     

Improvement and Experiment of the Reamer in Vibra Cutter Against Wave Edge of Titanium Sheet Alloy Parts

By analyzing the influencing factors of part quality making of sheet alloy of titanium by vibra cutter, the shape of upper reamer is set as cylinder and wedge-shaped form, and the lower reamer as plain and hemicycle form, and its main structural parameters are defined as well. Then it is validated further that such improved vibra cutter reamer can be used to process curve-edged parts of titanium alloy sheet. The experimental result shows that the titanium alloy sheet parts processed by above equipment have no sharpen angles for convex parts and evident crevasse of concave-edged part. In summary, such improvement can eliminate the free-waved edge and improve the manufacture quality of titanium alloy sheet parts greatly.     

Experimental Study on the Small Flyer Initiating Behavior of Fine-grained Explosives

The initiating behavior of fine-grained explosives by small flyer is studied. The diameter of small flyer in this device is 1 ram. The test results indicate that the granularity of explosives has great effect on its flyer initiating sensitivity.The flyer initiating sensitivity of the fine-grained explosives is higher and the critical initiating energy is lower than that of common explosives. For common explosive, the flyer initiating sensitivity increases as the density is reduced. But for the fine-grained explosive, the test results are exactly opposite.     

Algorithm for Multi-laser-target Tracking Based on Clustering Fusion

Multi-laser-target tracking is an important subject in the field of signal processing of laser warners. A clustering method is applied to the measurement of laser warner, and the space-time fusion for measurements in the same cluster is accomplished. Real-time tracking of multi-laser-target and real-time picking of multi-laser-signal are introduced using data fusion of the measurements. A prototype device of the algorithm is built up. The results of experiments show that the algorithm is very effective.     

Influence of Installing Error on the Surface Shape Precision of the Axial Symmetry Aspheric Workpiece in Lapping

A method to calculate the surface shape error, which is caused by the installing error between the workpiece and the lapping tool in the process of form lapping, is proposed. The mathematical model which the installing translation error influences on the workpiece surface shape error is established. The changing rule of the error is simulated through the calculating example of the paraboloid workpiece. The results indicate that the surface shape error of the workpiece is increasing with the increase of the installing translation error, it is also increasing gradually along the center point of the curve surface to the edge, and the influence is severer to the curve surface with great curvature than that of the small curvature when the translation error is the same.