某新型炸药冲击起爆试验与临界起爆特性研究

采用平面波发生器爆炸驱动不同厚度的飞片撞击带隔板装药,获得了某新型炸药与THAL,炸药的冲击波起爆临界隔板厚度.基于一维冲击波传播理论,建立了炸药临界起爆特性参数分析模型,并利用所测的两种炸药冲击波起爆临界隔板厚度,结合炸药及隔板材料的冲击Hugoniot参数测试结果,计算得到了两种炸药的冲击波临界起爆压力和起爆能量常数.     

高聚物粘结炸药冲击起爆统计热点反应速率模型

为深入探索非均质固体炸药冲击起爆热点机制,重点关注炸药孔洞尺寸分布及热点点火临界条件,建立高聚物粘结炸药(PBX)冲击起爆统计热点反应速率模型,描述热点形成、形核或消亡、点火后燃烧反应演化直至快速转为爆轰的全过程。奥克托今（HMX）基PBX9501和三氨基三硝基甲苯（TATB）基LX-17炸药冲击起爆过程的数值模拟结果显示,反应流场中波到达时间的计算值与实验值偏差小于3.7%,初步验证了统计热点反应速率模型的合理性,且相比文献［21-24］的统计模型适应性更强。研究结果表明：孔洞尺寸分布对非均质固体炸药冲击起爆感度影响显著;HMX基PBX炸药冲击起爆爆轰成长过程呈加速反应特性,而TATB基PBX炸药表现为稳定反应特性,进一步提高了对HMX/TATB混合基钝感高能炸药冲击起爆机理的认识。     

非理想高聚物粘结炸药冲击起爆反应流场拉格朗日分析

为对比奥克托今(HMX)基和三氨基三硝基苯(TATB)基高聚物粘结(PBX)炸药冲击起爆反应流场的差异,研究非理想PBX炸药冲击起爆爆轰成长特性,采用拉格朗日分析方法,分别以PBXC03(以HMX为主)和PBXC10(以TATB为主)炸药拉氏实验获得的压力历史曲线作为输入量。构造径线,对守恒方程进行积分,求得冲击起爆反应流场中质点速度、相对比容以及比内能的变化。比较PBXC03和PBXC10炸药反应流场,结果显示PBXC10炸药在冲击波阵面后没有明显的质点速度增长过程,能量释放过程发生在冲击波阵面处。这表明HMX基和TATB基PBX炸药爆轰成长过程的物理机制存在较大差异。     

飞片冲击起爆高能钝感高聚物粘结炸药的实验研究

为了对比奥克托今（HMX）基和三氨基三硝基苯（TATB）基高聚物粘结（PBX）炸药冲击起爆爆轰建立过程的差异,研究高能钝感炸药的爆轰成长特性,采用火炮驱动铝飞片实现平面冲击加载,建立一维拉格朗日锰铜压阻实验测试系统,得到高能PBXC03(以HMX为主)和高能钝感PBXC10(以TATB为主)炸药冲击起爆爆轰成长过程的不同拉格朗日位置处压力变化历史和前导冲击波时程曲线。结果表明：高能钝感PBXC10炸药的爆轰建立过程与高能PBXC03炸药明显不同,HMX基和TATB基PBX炸药冲击起爆和爆轰成长的物理机制存在较大差异。基于所得数据可标定高能钝感PBX炸药的反应速率方程。     

TATB基PBX的快速烤燃实验与数值模拟

根据TATB基高聚物黏结炸药(TATB基PBX)异常环境安全性特点(例如导弹发射失败),采用固体推进剂作为燃料开展了带2 mm厚约束钢壳的TATB基PBX快速烤燃小尺寸实验,模拟推进剂燃烧时具有一定约束炸药的响应情况,并且利用实验得到的炸药表面热流通量作为边界条件,采用高阶有限元法对炸药样品升温过程进行了数值模拟。实验中测量了炸药表面温度随时间变化情况,利用温度数据和Duhamel叠加原理计算得到炸药表面平均热流通量在其点火前为19.17 kW.m-2,在此平均热流通量条件下,带2 mm厚约束钢壳的TATB基PBX点火反应时间为95 s。研究结果表明,固体推进剂燃烧会在短时间内引起TATB基PBX点火燃烧反应,但不会发生猛烈的爆燃或爆轰现象。     

75℃下TATB基高聚物粘结炸药爆轰性能

为研究TATB基高聚物粘结炸药（ PBX）在高温下的爆轰性能,采用标准隔板试验、电测法、ZWB253-2008标准方法和圆筒试验测试了其在25℃和75℃下的冲击波感度、爆速、爆压及比动能。结果表明,与25℃相比,75℃下TATB基PBX的冲击波感度和比动能增大,爆速降低,爆压无明显变化。     

聚能射流侵彻隔板形成的前驱冲击波起爆不同温度炸药特性

弹药在聚能射流作用下的反应机制和响应规律,对弹药安全性研究具有重要意义。针对隔板中前驱冲击波起爆炸药机制及炸药温度的影响,开展实验和数值模拟研究。设计大尺寸装药聚能射流侵彻不同厚度隔板,起爆加热炸药的实验装置,采用上下两端加热和侧面保温的方式,实现炸药均匀加热和温度控制。选取黑索今(RDX)含铝(Al)炸药(炸药配方质量比：RDX∶Al∶粘结剂为61%∶30%∶9%)在不同温度和隔板厚度下进行射流侵彻起爆实验,基于脉冲X光高速照相法,观测射流侵彻过程及炸药爆轰波成长。建立考虑炸药温度变化的射流起爆炸药计算模型,对射流侵彻隔板形成的前驱冲击波起爆炸药进行数值模拟。结果表明：射流侵彻厚隔板形成的前驱冲击波,先于射流到达炸药表面,在传入炸药一定深度后起爆炸药。入射压力介于3.1 GPa和5.13 GPa 之间,炸药发生隔板中前驱冲击波起爆,入射压力高于5.13 GPa为直接冲击起爆。RDX含铝炸药温度对前驱冲击波起爆炸药有很大影响,在25~111 ℃时,随着温度升高,炸药受粘结剂软化的影响为主,RDX含铝炸药对冲击波感度降低;但超过一定温度后,在111~150 ℃时,粘结剂的影响减弱,冲击感度主要受RDX炸药感度的影响,冲击感度又会增加。     

聚能射流侵彻隔板形成的前驱冲击波起爆不同温度炸药特性

弹药在聚能射流作用下的反应机制和响应规律,对弹药安全性研究具有重要意义。针对隔板中前驱冲击波起爆炸药机制及炸药温度的影响,开展实验和数值模拟研究。设计大尺寸装药聚能射流侵彻不同厚度隔板,起爆加热炸药的实验装置,采用上下两端加热和侧面保温的方式,实现炸药均匀加热和温度控制。选取黑索今(RDX)含铝(Al)炸药(炸药配方质量比:RDX∶Al∶粘结剂为61%∶30%∶9%)在不同温度和隔板厚度下进行射流侵彻起爆实验,基于脉冲X光高速照相法,观测射流侵彻过程及炸药爆轰波成长。建立考虑炸药温度变化的射流起爆炸药计算模型,对射流侵彻隔板形成的前驱冲击波起爆炸药进行数值模拟。结果表明:射流侵彻厚隔板形成的前驱冲击波,先于射流到达炸药表面,在传入炸药一定深度后起爆炸药。入射压力介于3.1 GPa和5.13 GPa之间,炸药发生隔板中前驱冲击波起爆,入射压力高于5.13 GPa为直接冲击起爆。RDX含铝炸药温度对前驱冲击波起爆炸药有很大影响,在25111℃时,随着温度升高,炸药受粘结剂软化的影响为主,RDX含铝炸药对冲击波感度降低;但超过一定温度后,在111150℃时,粘结剂的影响减弱,冲击感度主要受RDX炸药感度的影响,冲击感度又会增加。     

ANPyO 和8701 的冲击波感度对比研究

为对比一种单质钝感炸药ANPyO和8701炸药冲击波感度方面的优劣,以小隔板试验为手段对2种炸药进行冲击波感度试验研究。以2种炸药的见证板的反应状况作为判定标准,得到冲击起爆时临界隔板厚度值,并结合试验结果对2种炸药的临界冲击起爆压力进行了理论计算。分析结果表明:ANPyO的临界起爆压力比8701大2个数量级,所以ANPyO炸药具有很低的冲击波感度,更值得引起炸药合成研究工作者的关注。     

不同加载压力下炸药冲击起爆过程实验和数值模拟研究

采用炸药平面透镜爆轰加载及空气与隔板综合衰减技术,建立基于锰铜压阻传感器的 一维拉格朗日实验分析系统,得到了3 种加载压力下两种颗粒度PBXC03 炸药冲击起爆不同拉格 朗日位置的压力历史,以及加载压力对炸药冲击起爆过程的影响规律。采用DYNA2D 程序,对两 种颗粒度PBXC03 炸药的冲击起爆过程进行数值模拟,计算结果与实验结果趋势一致。结果均表 明:加载压力减小,炸药中前导冲击波速度增长变慢,压力增长变缓,炸药的到爆轰距离增加。数值 模拟得到的两种颗粒度PBXC03 炸药起爆压力和到爆轰距离的关系与文献[15] 的POP 图曲线吻 合较好,验证了文献[14]建立的PBX 炸药冲击起爆细观反应速率模型的合理性。     

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.     

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.     

Research on Gear-broken Fault Diagnosis in a Tank Gearbox

A fault diagnosis method of working position gear in a tank gearbox is put forward based on simulating the fault of working position gear in an actual tank, extracting the envelope of vibration signal by Hilbert transformation amplitude demodulation method, and zooming the low-frequency band to envelope signal.