基于激光光幕和光电二极管阵列的立靶坐标测量

为了实现高精度、大面积的立靶坐标测量,提出了一种大面积激光光幕子弹弹着点坐标测试的新方法.采用4个扇形激光光幕相互交叉组合成大面积矩形光幕,利用光电二极管阵列测量激光光幕的光强,当子弹穿过激光光幕时,相应的光电二极管接收到信号,经信号采集和处理电路计算出子弹弹着点的坐标.对有效靶区1m×1m的原理样机进行7.62mm枪弹实弹射击实验,实验结果表明坐标测量精度达到2mm.该方法结构简单,易构造较大面积的靶面,其最大有效靶区可达到10m×10m.     

基于工程模型的六光幕阵列天幕立靶弹头坐标测量不确定度评定方法研究

六光幕阵列天幕立靶是测量速射武器连发弹头着靶坐标的主要设备。针对现有光幕阵列理想模型下测量不确定度分析无法满足其工程实际中测量需求的不足,在理想模型和工程模型下综合考虑双N形六光幕阵列测量不确定度的影响因素,仿真分析了光幕阵列结构参数不确定度、布靶参数不确定度、过幕时刻序列不确定度、光幕垂直度不确定度、靶体水平和平行布放不确定度及弹头速度方向角等各项因素对着靶坐标测量不确定度的影响规律。通过建立的评价函数对各因素的影响作用进行评价。结合工程实际对所有因素影响下的不确定度进行合成,得到选定的1 m× 1 m靶面内不确定度分布。试验表明,实弹测量结果与分析结果具有较好的一致性。     

CCD立靶靶面不重叠误差分析

应用CCD立靶时操作不慎造成的靶面不重叠降低了测量精度,有必要对靶面不重叠误差进行分析。通过研究坐标求解模型,将靶面不重叠对结构模型的影响转化为弹丸在CCD像面上成像位置的偏差,推导了三种靶面不重叠情况下成像位置的计算公式。对8m×8m靶面内的误差分布进行了仿真。结果表明:由平行和水平夹角不重叠造成的最大测量误差小于1mm;由垂直夹角不重叠造成的最大测量误差超过6.8mm,对测量精度影响较大。     

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.     

弹着点坐标的组合光幕阵列测量方法

为了精确测量兵器外弹道试验中弹丸着靶坐标,采用光电管和线阵CCD成像器件分别构建模拟光幕和图像细分光幕,3个模拟光幕与1个图像细分光幕构成四组合光幕阵列,4个模拟光幕与1个图像细分光幕构成五组合光幕阵列.给出了组合光幕阵列测量着靶坐标的原理,分析了测量误差并进行了仿真.结果表明所提方法能实现射击弹丸的弹着点坐标的测量,在2m×2m靶面测量误差小于1.7mm,与六模拟光幕阵列相比,提高了测量精度,简化了阵形结构.     

CCD交汇光靶布站方式的优化设计与数值模拟

在介绍CCD交汇光靶原理的基础上,利用数学模型分析了坐标测量精度与相机系统各结构参数之间的关系,通过计算机仿真技术对光靶的布站方式进行了数值模拟.结果表明,在给定靶面尺寸及各结构参数测量误差的前提下,可以得到使系统坐标测量误差最小的最佳布站方式.     

数据包络分析在防空兵作战方案优选中的应用

根据防空兵作战方案要素建立的作战方案评估指标体系,可运用数据包络分析C2R评估模型分析其方案输入与输出指标.其评价指标的选取包括作战准备时间、弹药投入、兵力耗损、毁伤目标及被掩护目标安全率等方面.从技术和规模有效两方面评价备选方案并得出结论,为防空兵作战指挥员优选作战方案提供了科学依据.     

弹丸速度及弹着点坐标测量系统研究

为了在武器速射系统研制中同时测量弹丸速度和弹着点坐标.采用平行点激光光束交叉形成光栅光幕靶,以PCI总线构成数据采集系统.采集64路数字信号.通过分析连发弹过靶信号,提取各个弹丸过靶位置判别值以及过靶时刻.计算得到连发多弹中各个单弹速度以及弹着点坐标.室内外靶场实弹测量实验结果表明,该测试方案可以同时测量高射频连发弹弹丸速度、射频、弹着点坐标.未出现弹序误判、漏判情况.该测试方案时连发弹道武器的研制和开发及测试"金属风暴"武器、弹阵分布具有参考价值.     

基于红外发光二极管和光敏元件阵列的光电靶

室内大靶面立靶精度测试系统一直是外弹道测试领域研究的热点.目前国内已出现的单靶面激光精度靶存在靶面增大后灵敏度不够、精度不高的问题.基于红外发光二极管和光敏元件阵列的光电靶可以提高灵敏度,有效地增大靶面.弹丸的探测通过X和Y方向各一组光传感器来完成,在靶面上与光传感器对应的另一侧装有红外LED光源,靶面的有效探测区域由光传感器与光源形成的光幕确定.弹丸通过靶面时由邻近的几个传感器单元探测到,并通过软件精确识别确定弹丸过靶的坐标.传感器通过设置灵敏度,可仅探测快速移动的物体,避免误触发.单靶能够测量射击精度、射击频率,给出弹序、弹丸的X、Y坐标和R50与R100,当连接两套或更多光电靶时可测量弹丸飞行速度和弹丸偏角及倾角.     

双等边三角阵声学靶测量原理

为了解决双等边三角阵声学靶测量弹着点坐标计算过程繁琐的问题,在局部将激波在预定靶平面上的曲面传播看成是平面传播,得到了激波在各个传声器之间传播的声程差与三角阵边长之间的几何关系,通过解三角形求得了弹着点的坐标测量公式.通过仿真计算对该坐标测量公式的理论误差进行了分析,在对4m×4m靶面的仿真中得到x、y坐标测量误差分别为±10mm和±25mm.仿真结果表明,该测量公式形式简单,且具有较高的精度.     

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.     

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.     

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 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.