具有负延迟的分区域数据存储方法

针对随机相似过程的测试中,采用连续采样模式存在大量冗余数据存储和系统存储容量不足的矛盾所导致有效数据无法完整存储的问题,提出了具有负延迟的分区域数据存储的方法。这种方法通过负延迟和存储器分区技术及方法实现了对触发前后的有效数据的存储和两个过程之间无效数据的不存储。对比与实验表明,对相同过程的测试,本方法与连续采样相比具有冗余数据少,存储容量利用率高的特点,为有效解决大量数据与存储器有限的矛盾提供了依据与方法。     

多通道瞬态信号自适应变频算法

为了解决在多通道瞬态信号测试领域,传统测试系统长时间高采样率测试产生的冗余数据对系统存储和传输带来的压力,提出了一种自适应变频算法。该算法采用与传统测试相同的采样率获取原始数据并以时间分段,依据每段信号的频域特征确定瞬态信号发生时刻和持续时间,对非瞬态信号进行二次采样,达到在完整保留瞬态信息的前提下减少冗余数据的目的。在实际爆炸冲击波场测试中进行验证,经过算法处理后数据压缩比大于33,同时保证瞬态信号持续期间数据完整,非瞬态信号持续期间最大误差小于0.5FS. 试验结果表明,该算法可有效减少瞬态测试过程中的冗余数据。     

基于闪存的引信电池大容量存储测试方法

针对现有引信电池存储测试采样频率低、存储容量小,不能满足引信电池放电测试时长时间记录的问题,提出了一种引信电池大容量存储测试方法。通过采用CPLD产生高频采样信号;采用大容量闪存存储数据,使用单片机控制两片闪存交替工作的模式来满足高速数据采样,并将存储容量扩大至1 024 MB。存储模块中设计了负延迟,完整地记录各工况下引信电池的输出。实验测试表明:大容量存储测试方法可将采样频率提高到1 MHz,记录时间延长到270 s。     

高速大容量双冗余机载雷达数据记录仪设计

针对高速机载雷达数据传输速度快、数据量庞大的特点,设计了一种基于FPGA的高速大容量双冗余载雷达数据存储系统。系统以FPGA为逻辑控制中心,采用高速FIFO和Flash流水线操作实现了高速雷达数据无缝缓存和连续高速存储,并采用二维无效块检测列表刷新算法保证了双冗余数据的可靠性,减少了FPGA内部资源的占用。试验结果表明:系统工作稳定,记录数据完整准确,能够实现对传输速率为24Mi B/s高速并行雷达数据的双冗余存储。     

水下冲击波超压高速存储测试系统的研究

针对当前水下冲击波超压测试中存在仪器布设繁杂、采样频率低、关键数据难以及时获取等问题,设计了一种水下冲击波超压存储系统.提出双级流水线循环存储结构实现数据高速存储,运用触发地址回溯检索算法精准定位有效数据存储位置,以ZigBee无线网络交互通信完成测试系统的智能配置、状态监控和关键数据及时提取.试验表明该系统能以10 MB/s的速率完整记录冲击波超压瞬态信号,具有智能化、易布设等特点,适用于水下冲击波超压信号的测试.     

侵彻过程中弹头表面瞬态温度测量系统

介绍了一种瞬态温度测量系统,用于测量与记录侵彻过程中弹体表面瞬态温度变化信号。该系统选用薄膜热电偶直接测量弹头侵彻温度,以C8051F340高速单片机为微控制器,控制温度数据的采集及存储。利用打火机内焰瞬态温升信号对系统进行静态测试,结果表明系统采样频率最高为300kHz,测量误差<1.5%,数据存储速率为800Kbps,可以满足后续射击实验的要求。     

分别采用正负延迟触发的存储测试方法

针对弹载存储测试系统中单一的负延迟触发方式稳定性不高,所测数据单一,测试电路集成度不高,数据易丢失等问题,提出了分别采用正负延迟触发的存储测试方法。该方法通路1以采样信号值的变化为触发信号,采用负延迟触发方式;通路2以发射击发机构运动为触发信号,采用正延迟触发方式。分析与试验表明:两种触发方式的结合,能够最大限度地减小外界干扰信号的影响,在数据采集过程中同步将数据存储于非易失存储器中,实时保存所测数据,有效提高了单次测试的可靠性,最大限度提高了系统的可利用性。     

可编程引信高速编码信号测试仪

针对模拟环境下可编程引信高频编码信号无有效测试装置的问题,提出了基于高速数据采集和存储技术的高速编码信号测试仪。该测试仪以高速AD转换器与FPGA为核心,根据编码信号的特点对其进行有效的衰减和差分化,增强了测试仪的抗干扰能力减小了测试误差,采用并行双通道时间交替采样技术实现了200 MHz的高采样频率,使用FPGA实现高速控制时序逻辑和数据分区缓存,避免了高速存储中可能产生的丢点情况。实验结果表明,高速编码信号测试仪具有完整的记录信号波形,能满足高频引信编码信号测试要求,可作为可编程引信高频编码信号测试的有效装置。     

高速弹载记录仪存储技术研究

针对弹载记录仪中NAND型Flash在负延时记录时写入速度低和可靠性差的问题,提出一种新型高速负延时存储方法。在研究NAND型Flash存储器存储介质访问原理的基础上,采用当前成熟的高速率流水线存储技术,设计了一种单通道双控制总线的高速存储结构,解决了当前具有负延时的弹载记录仪存储速度的瓶颈问题。以 SOPC技术为基础,将整个控制系统构建在单片 FPGA上提高可靠性。试验结果验证了该存储体系结构单通道写入速度可达最高理论值40 MB／s,负延时容量、存储总容量根据要求可设置。     

抗冲击数据记录仪数据高速回读技术研究

抗冲击数据记录仪广泛用于航弹飞行数据的记录,其记录的信号通道多,存储的数据量大,将记录仪中的数据高速回读并实时存储到计算机中是个技术难题。文中以LABVIEW8.5为软件开发平台,采用USB总线作为数据回读传输总线,详细介绍了系统软硬件接口设计、数据动态存储以及高速回调技术,实现了16通道测试数据以1MB/s的速度由记录仪硬件向计算机高速回读的功能,解决了试验现场数据的高速回放、存储与分析问题。飞行试验应用表明,该系统运行稳定可靠,数据回读迅速、正确。     

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.