TDI-CCD光靶弹着点坐标测量误差分析

TDI-CCD光靶测量精度是衡量其性能的一个重要指标,为分析光靶坐标的测量误差,将靶心及靶面边缘的若干个点作为误差计算的特征点,对光靶的结构参数进行了优化设计.通过计算和仿真,得到了光靶测试范围内各点坐标综合误差分布.在搭建CCD光靶实验系统的基础上,用模拟弹丸验证了靶面坐标的测量误差.结果表明,CCD靶面弹丸落点坐标近似等于木靶靶面的落点坐标,实验结果与计算吻合较好.     

燃烧轻气炮弹裙挤进变形及应力分析

针对燃烧轻气炮和弹丸的结构特点,分析了弹丸弹裙与坡膛之间的挤压变形过程;建立了弹丸弹裙和身管模型,根据模型进行了数值模拟,得出了弹裙应力-时间曲线、速度-时间曲线和位移-时间曲线,指出弹裙高度对弹丸初速的影响.研究结果可为弹丸弹裙优化设计提供依据.     

地面火炮射程的外弹道优化设计

本文以射程为优化目标,对火炮弹丸在全弹道上从气动力、外弹道等诸性能方面进行了系统综合优化,同时,对火炮、弹丸外弹道优化理论中的一些问题进行了探讨,建立了优化设计数学模型,并采用数学规划方法求解,编制了相应的计算程序。利用该计算程序,只要根据下达的设计任务输入一些已知参数(如炮口能量、膛线缠度等),就可对弹丸最大射程的外弹道优化设计进行计算,给出最佳的弹重、初速、弹形参数等主要设计参数。文中还对175mm火炮弹丸进行了优化设计计算,并与原方案进行了比较.另外,利用该程序还可进行优化计算在满足一定射程时所需的最小炮口能量。     

一种测试弹丸落炸点的数学模型于

为了解决弹丸落炸点坐标的实时、动态和精确测试,分析和推导了光学交汇法的数学模型.首先根据弹丸着地前某时刻通过两台面阵CCD时分别在各自像片坐标系上所成像的像点坐标,经过坐标系转换得到其大地坐标系下空间坐标,再推导出各自像点和物镜焦点所在的直线方程,由预先给定的两条直线公垂线长度门限值对像点进行取舍判断,计算出这两条直线的近似交点即为该时刻弹丸空间点坐标.从而为模拟弹丸着地前弹道运动轨迹、求解弹丸落炸点坐标建立了基础.经过靶场试验验证,该测试方法更适用于远程和大口径火炮弹丸终端参数的测试.     

迫击炮弹丸与身管配合间隙优化设计

针对迫击炮弹丸出炮口时的尾翼颈部折断问题,考虑弹丸前定心部与膛壁的摩擦,建立了迫击炮弹丸与身管耦合系统的有限元模型,对弹丸膛内运动过程进行了仿真计算,得到弹丸起始扰动,以出炮口时刻弹丸起始扰动的位移、角位移和角速度构建优化目标函数,以弹丸与身管配合间隙为设计变量,基于Isight软件提供的多目标优化方法对弹丸起始扰动进行优化设计,得出了相对最优配合间隙值。结果表明,迫击炮弹丸与身管配合间隙对弹丸起始扰动影响显著,优化后出炮口时刻弹丸质心位移、角位移和角速度均明显减小,该结果对迫击炮弹丸与身管的匹配设计具有一定参考价值。     

基于快速互相关的跨声速弹丸测速方法研究

针对室内千米靶道内镜头式光幕测速系统无法对跨声速弹丸速度进行有效测量的问题,采用外弹道学理论与MATLAB仿真技术计算跨声速测速点弹丸飞行速度理论值,使用快速互相关算法处理镜头式光幕测速系统在测速点的弹丸过幕信号,得到该测速点的实测速度值集合,以理论速度值为参考,从速度值集合中选取接近理论值的速度并进行误差分析。采用5.8 mm步枪弹进行实弹验证,实验所得的接近理论速度值的实测速度与理论值之间的相对误差小于0.3%。该方法解决了由于弹丸激波作用测速光幕产生干扰信号带来的影响,为跨声速弹丸速度的准确测量提供一种新思路。     

小口径榴弹集成优化模型与方法研究

为提高小口径榴弹设计性能,缩短设计周期,建立了包括结构、内弹道、外弹道、杀伤威力以及武器后坐力5个分析计算模型的集成优化设计模型.应用模拟退火算法,分别以最大杀伤面积、最短弹丸飞行时间以及杀伤威力与武器后坐力综合性能为目标对榴弹进行了集成优化设计.与原设计相比,杀伤威力提高39%,弹丸飞行时间缩短5%,杀伤威力提高38%,后坐力降低44%.得到了榴弹各目标性能最优时的结构参数、装药参数、射击条件及单兵武器缓冲器参数.该研究为小口径榴弹的设计提供了一种新方法.     

起爆方式对切割式多爆炸成形弹丸成形影响分析

利用LS-DYNA仿真软件对切割式多爆炸成形弹丸成形过程进行了数值模拟,模拟结果与网靶试验结果吻合较好.在此基础上进一步研究了起爆方式对弹丸速度和质量的影响.研究表明:该战斗部经网栅切割后能形成5枚具有一定质量和方向性的弹丸,有效提高了毁伤元的数量和毁伤面积;采用平面起爆方式时,中心与周边弹丸速度比点起爆分别提高了46％和28％,有效地增加了弹丸速度;随着弹丸速度的增加其质量降低,采用点起爆时弹丸质量最大,而平面起爆时最小,因此可根据具体目标选择合适的起爆方式,以提高对目标的打击毁伤概率.     

Projectile＇s Speed and Attitude Measured by Linear Camera

为测定弹丸的瞬时速度与姿态,利用标定过的线阵像机,在镜面摄像法下从2个视角对运动中的弹丸进行扫描成像.在研究了线阵像机的动态成像方程后,利用若干个目标特征点和对应的图像点,建立测量问题数学模型;通过两步法求解出弹丸的速度、姿态和初始位置8个参数.对不同像机参数下的不同弹丸几何尺寸和不同的运动姿态参数进行了图像仿真和测量实验,结果表明算法的姿态测量误差优于0.4°,合速度的相对测量误差优于2%.利用线阵像机成像模型和最优化算法测量弹丸速度与姿态参数具有较高的精度.     

基于线阵像机的弹丸速度与姿态测量

为测定弹丸的瞬时速度与姿态,利用标定过的线阵像机,在镜面摄像法下从2个视角对运动中的弹丸进行扫描成像.在研究了线阵像机的动态成像方程后,利用若干个目标特征点和对应的图像点,建立测量问题数学模型;通过两步法求解出弹丸的速度、姿态和初始位置8个参数.对不同像机参数下的不同弹丸几何尺寸和不同的运动姿态参数进行了图像仿真和测量实验,结果表明算法的姿态测量误差优于0.4°,合速度的相对测量误差优于2%.利用线阵像机成像模型和最优化算法测量弹丸速度与姿态参数具有较高的精度.     

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.     

Stability of the Third Generation Intensifier under Illumination

The stability under illumination of transmission-mode GaAs photocathode sealed in the third generation intensifier is investigated by use of spectral response testing instruments. The variations of spectral response with the illumination times under weak and intense illumination are compared. The variations of photoemission performance parameters are also characterized. The results show that during initial several weak illuminations photocathode behaves no evident decay and a maximum sensitivity is achieved, while under intense illumination the sensitivity of photocathode begin to decrease largely at the first illumination. The calculated performance parameters show that the variation of surface escape probability with illumination times is a direct cause of instability of photocathode. It is also found that under intense illumination peak wavelength is moved towards short-wave and peak response is decreased, which shows that the ability of long-wave response of photocathode is decreased.     

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.     

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.     

Passive Acoustic Radar for Detecting Supersonic Cruise Missile

A Passive Acoustic Radar is presented as a necessary complement to electromagnetic wave radar, which will be expected to be an effective means for detecting cruise missiles. Acoustic characteristics of supersonic flying projectiles with diverse shapes are expounded via experiment. It is pointed out that simulation experiment could be implemented using bullet or shell instead of cruise missile. Based on theoretical analysis and experiment, the ““acoustic fingerprint““ character of cruise missile is illustrated to identify it in a strong noise environment. After establishing a locating mathematical model, the technique of acoustic embattling is utilized to resolve a problem of confirming the time of early-warning, considering the fact that velocity of sound is much slower than that of light. Thereby, a whole system of passive acoustic radar for detecting supersonic cruise missile is formed.     

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.     

Robust Graded Sliding Mode Tracking Control for Low Speed Spinning Ballistic Missiles

The nonlinear dynamic model of spinning ballistic missiles is established during the first boosting phase of the missile. Based on the conventional backstepping sliding mode control and the assumption of a two time-scale separation of missile dynamics, a graded sliding mode controller is designed with two sub-sliding surfaces which have invariability to external disturbances and parameter perturbations, and a matrix which comprises three first order low pass filters is introduced to prevent ＂explosion of terms＂. Owing to the upper bounds of the uncertainties are difficult to obtain in advance, adaptive laws are introduced to estimate the values of the uncertainties in real-time. Eventually, the numerical simulation results given to show the proposed controller can ensure the steady flight of missiles.