液氢液氧火箭发动机用点火器的高空点火试验

日本宇宙开发事业团正在进行研制的液氢液氧火箭发动机的主点火器和燃气发生器用的点火器,在低压(约10乇)环境下共进行点火试验194次,累计时间1440秒。点火试验条件:点火燃料入口温度从130K到常温;点火器燃烧室压力为1～4公斤/厘米~2·绝;混合比为0.5～1.5。主点火器的燃烧室压力为1公斤/厘米~2·绝左右时,往往点火延迟、燃烧效率降低。流入的氢氧温度越低,越不容易点着火。液氧流入时间偏差±0.1秒(超前或滞后)对点火特性没有影响。已试验过的四种励磁式火花塞中,电极为纯镍材料,具有二次间隙电容放电式的火花塞,点火可靠性高。燃气发生器用点火器在燃烧室压力为1～7公斤/厘米~2·绝时点火性能良好,特征排气速度效率为90～95％。经过试验也测出了主点火器的点火界限和点火器燃烧室出口处的温度分布。     

3种点火药点火性能试验研究

以常用点火药剂NC(硝化棉)、奔奈和BP(2~#小粒黑)作为点火药,以点火延迟时间及特征点火药量作为点火性能判据,考察了3种点火药的点火性能。点火性能实验结果表明:BP点火延迟时间最短,电热镍镉桥丝点火时间约23ms;奔奈点燃发射药的能力最强,点燃RGD7A基发射药特征点火药量较NC和BP少6%;使用BP和奔奈作为点火药,可使装药的点火燃烧速度提高。     

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。     

斯蒂芬酸铅的半导体桥点火试验研究

通过对半导体桥(Semiconductor Bridge,SCB)装药条件下发火电压、发火电容及积分能量对点火时间影响的对比,结合不同点火条件下,桥体两端电压曲线、电流曲线和电流二次峰出现时间的比较,研究了斯蒂芬酸铅(LTNR)的半导体桥点火机理。试验发现特定的点火电路下,SCB点火时间存在一个临界值,且SCB等离子体形成的快慢直接影响点火时间。在充电电压从大到小的点火过程中,在桥与药剂之间存在2种不同的点火机理,在较高点火电压下为等离子体点火机理,在低电压为热点火机理。     

某导弹点火装置B-KNO3输出装药设计及试验

为了实现某导弹发动机的稳定点火，对点火装置B—KNO3输出装药的药型和药量进行了设计及试验，确定了点火药量为（2．5±0．1）g，药型为环状，并通过相关试验验证了B-KNO3输出装药的强度及输出性能，验证试验表明B-KN03输出装药满足发动机点火要求。     

长药室装药中多点点火技术试验研究

为解决大口径火炮长药室装药轴向点传火问题,针对药室长度超过3 m的长药室装药,设计了多点点火系统,进行了多点点火研究.运用高速摄像研究了点火头的发火一致性,结果表明,C型点火头4 ms内全部点燃,发火一致性高于A型和B型;测量了不同长度的多点点火管的压力-时间曲线,结果表明,两节和四节模拟装置试验p-t曲线基本重叠,时...     

一种含HMX的新型高能点火药

采用理论计算与试验方法对某含HMX的高能点火药性能进行了研究。结果表明：理论计算与试验结果基本相符,随着HMX含量的增加,该点火药输出能量变化小,爆热值均大于9000J／g;残渣量略有减少,均大于80％;同时,药剂比容明显增大。热分析实验表明：HMX与Mg-Al合金、KClO4具有良好的相容性,加入HMX后点火稳定性增强;感度测试结果表明：HMX含量从5％增加至10％时,点火药的撞击感度增加,摩擦感度与火焰感度无显著变化。     

纳米多孔铜/高氯酸钠复合物电点火头的原位制备方法

为制备纳米多孔铜/高氯酸钠复合物电点火头,以焊有桥丝的脚线为阴极,大面积紫铜片为阳极,采用电沉积法在桥丝上原位沉积纳米多孔铜;将沉积有纳米多孔铜的桥丝浸入高氯酸钠饱和溶液制得纳米多孔铜/高氯酸钠复合物电点火头.采用SEM,EDS,XRD等手段对复合物进行表征,采用DSC研究了复合物的热分解性能,表明在402.09℃处有一尖锐的放热峰,放热量为171.8J/g.采用直流发火和脉冲电流发火的方法测得电点火头50%发火感度分别为0.55A和0.47A,两种测量方法的标准偏差分别为0.114和0.005;且在22μF电容、32V的测试条件下电点火头不发火.该方法将火工品药剂的原位合成与火工品的制造有效结合,避免了电点火头生产过程中操作者与药剂的直接接触,有利于提高生产过程中的安全性.     

底排点火具在大气中燃烧火焰扩展特性

底部排气弹射程和纵向密集度与点火具的工作性能密切相关。采用高速录像系统和红外热像仪研究了大气环境中,镁/聚四氟乙烯(MT)(Mg/PTFE 45/55、Mg/PTFE 55/45、Mg/PTFE 61/39)、硝酸钡(Ba(NO_3)_2)和氢化锆/氧化铅(ZrH_2/PbO_2 40/60)五种点火药剂在不同点火具孔径(6.5,8mm)下的燃烧扩展特性,并测得七种点火具的火焰温度场分布。在实验基础上,以基于内节点的有限体积法对MT点火具的燃烧射流场进行三维数值模拟,分析了不同MT质量比和点火具孔径下点火具在大气中的燃烧特性参数分布规律。实验和数值结果表明:ZrH_2/PbO_2点火具会破坏底排推进剂的"平行层"燃烧规律;提出以点火面积有效因子表示推进剂点火面积的有效程度,并结合点燃时间综合评估点火具的点火性能,发现MT质量比为61∶39,孔径为8mm的点火具性能最优;点火具火焰最高温度区均位于喷孔的势流核上方;镁质量分数为0.45~0.61时,镁含量越小,MT点火具燃烧场中火焰温度越高,镁含量一定,点火具孔径为6.5,8mm时,较大孔径有较强烈燃烧场热对流,较高中心轴向温度,较大温度梯度。     

不同加速寿命时间点上不同桥丝材料电阻变化研究

在恒定温度、湿度的条件下,研究了镍络丝和金丝两种不同桥丝材料的电极电阻在加速寿命试验后各个不同贮存时间点的变化情况,并对不同寿命时间点的电阻均值进行t-显著性检验。研究结果表明,金丝电极电阻在室温下贮存20天及在温度(50±2)℃、湿度95%条件下贮存9天、14天和21天后都较初始电阻有显著性变化,而镍铬丝电极电阻却变化不明显。     

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.     

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.     

Super-resolution Restoration of Remote-sensing Images

A novel image restoration scheme, which is super-resolution image restoration algorithm Poisson-maximum-afterword-probability based on Markvo constraint （MPMAP） combined with evaluating image detail parameter D, has been proposed. The advantage of super-resolution algorithm MPMAP incorporated with parameter D lies in the fact that superresolution algorithm MPMAP model is discrete, which is in accordance with remote-sensing imaging model, and the algorithm MPMAP is proved applicable to linear and non-linear imaging models with a unique solution when noise is not severe. According to simulation experiments for practical images, super-resolution algorithm MPMAP can retain image details better than most of traditional restoration methods; at the same time, the proposed parameter D can help to identify real point spread function （PSF） value of degradation process. Processing result of practical remote-sensing images by MPMAP combined with parameter D are given, it illustrates that MPMAP restoration scheme combined PSF estimation has a better restoration result than that of Photoshop processing, based on the same original images. It is proved that the proposed scheme is helpful to offset the lack of resolution of the original remote-sensing images and has its extensive application foreground.     

Design and Simulation of TF and TA Controller for Missile

A nonlinear terrain following(TF) and terrain avoidance(TA) controller is proposed for missile control systems. Based on classical TF algorithm (adaptive angle method), a new method for TF controller is proposed by using angle of attack. A method of obtaining terrain outline data from digital elevation map (DEM) for TF control is discussed in order to save store space. A TA algorithm is proposed by using bank-to-turn technique. The block control model, which is suitable for backstepping design, is given for nonlinear model of missile. Making full use of the characteristics of the system and combining block control principle and backstepping technique, a robust controller design method is proposed. Uncertainties in every sub-block are allowed, and can be canceled by using the idea of nonlinear damping. It is proved that the state tracking errors are converged to a neighborhood of the origin exponentially. Finally, nonlinear six-degree-of-freedom simulation results for the missile model are presented to demonstrate the effectiveness of the proposed control law.     

Design and Analysis of Test Schemes of Static Postponing Time on Shrapnels Used to Riot Control

The test scheme of static postponing time given in our actual national military test standard on shrapnels used to control riot is a nine-point test scheme on the combined action of three kinds of temperatures and three kinds of pressures,the consumed ammunitions are more excessive. Statistic analysis and tentative checkout about a lot of test data are done,feasibility gists are put forward for optimizing of the test design scheme. The optimizing design and data analysis of test scheme of the item are done by managing uniformity design theory, two scientific and reasonable six-point test schemes are confirmed. The feasibility and reliability of the optimizing design schemes put forward above are proved ulteriorly by test validating. The gained schemes not only have good design uniformity and little ammunition wastage and meet the test demand, but also have better forecast ability for the result data of other points using the mathematic models from the actual test points.     

Expert Systems Aimed at General Design of Projectiles

Expert systems aimed at the general design of projectiles can implement a series of intelligent designs, such as the design of HE shell, the scheme expounded and proved, the emulation analysis and calculation, etc. Aiming at the product design feature, the expert system adopts the object-oriented knowledge representation and all kinds of inference control engines to describe and reason the relevant knowledge regarding the product through the microcomputer. It embodies the foundation of emulation analysis and simulated manufacturing of the shell. It makes use of the method that knowledge expression is combined with condition of inference to carry out the overall design and emulation and reference.The paper gives the ways through which the functions can be achieved, gives the modularization of reference and the design methods of systematization, puts forward the method of knowledge expression and working interface, and supplies a platform for similar products of the shell category that can be quickly designed.     

Design of Non-fragile Satisfactory Estimator for Linear Continuous Perturbed Stochastic Systems

The design problem of non-fragile estimator is addressed for a class of perturbed linear continuous systems. The perturbations occur on the plant and estimator parameters. The estimator designed should force the error system to achieve the desired decay rate and force the steady error variance less than the specified upper bound irrdevancy of the admissible plant perturbations and estimator perturbations. Consistency problem of the decay rate with the variance upper bound is first considered via linear matrix inequality （LMI） approach. The solution of the estimator parameter under specifications to be consistent is then discussed. The consistency condition of specifications and estimator parameter solution are transformed to feasible or minimum problems subject to a set of LMI respectively. The method is illustrated by a numerical example.     

An Improved Scene-based Nonuniformity Correction Algorithm for Infrared Focal Plane Arrays Using Neural Networks

The improved scene-based adaptive nonuniformity correction （NUC） algorithms using a neural network （NNT） approach for infrared image sequences are presented and analyzed. The retlna-like neural networks using steepest descent model was the first proposed infrared focal plane arrays （IRFPA） nonuniformity compensation method, which can perform parameter estimation of the sensors over time on a frame by frame basis. To increase the strength and the robustness of the NNT algorithm and to avoid the presence of ghosting artifacts, some optimization techniques, including momentum term, regularization factor and adaptive learning rate, were executed in the parameter learning process. In this paper, the local median filtering result of Xij （ n ） is proposed as an alternative value of desired network output of neuron Xij （ n ）, denoted as Tij （ n ）, which is the local spatial average of Xij （ n ） in traditional NNT methods. Noticeably, the NUC algorithm is inter-frame adaptive in nature and does not rely on any statistical assumptions on the scene data in the image sequence. Applications of this algorithm to the simulated video sequences and real infrared data taken with PV320 show that the correction results of image sequence are better than that of using original NNT approach, especially for the short-time image sequences （several hundred frames） subjected to the dense impulse noises with a number of dead or saturated pixels.     

Piecewise Filter of Infrared Image Based on Moment Theory

The disadvantages of IR images mostly include high noise, blurry edge and so on. The characteristics make the existent smoothing methods ineffective in preserving edge, To solve this problem, a piecewise moment filter （PMF） is put forward. By using moment and piecewise linear theory, the filter can preserve edge. Based on the statistical model of random noise, a related-coefficient method is presented to estimate the variance of noise. The edge region and model are then detected by the estimated variance. The expectation of first-order derivatives is used in getting the reliable offset of edge. At last, a fast moment filter of double-stair edge model is used to gain the piecewise smoothing results and reduce the calculation. The experimental result shows that the new method has a better capability than other methods in suppressing noise and preserving edge.     

Bistatic Sonar Localization Based on Best Linear Unbiased Estimation

A best linear unbiased estimation （BLUE） algorithm for bistatic sonar localization is proposed. The Cramer-Rao bound for bistatic Sonar and the geometrical dilution of precision （GDOP） in different conditions are given. The simulation results show that the location accuracy of BLUE algorithm is higher than the weighted least square method.