基于单片机与FPGA的等精度频率计设计

根据等精度测频原理,利用单片机与FPGA结合设计等精度数字频率计。待测频率信号经过整形放大后输入到FPGA,单片机控制FPGA通过内部脉冲计数器对待测信号和标准信号源同时计数,单片机读回测频数据后,经运算处理后显示。等精度频率计测频精度高,且精度不随频率的变化而变化。单片机与FPGA结合,测频速度快,范围宽,可靠性高。     

程控调幅多路并行信号源

针对传统多路并行信号源存在幅值不灵活可调且成本高的缺点,设计了基于FPGA和DDS技术相结合的程控调幅多路并行信号源。该信号源在FPGA内实现DDS的资源优化,利用DDS原理配合FPGA无缝式内部访问IP Core方式实现频率可调;利用FPGA内部程序设计对归一化的数字量进行调制及转换实现幅值可调。实验表明:该信号源可并行输出32路高精度信号,输出信号的频率、幅度、波形等均可由用户按实际需求通过上位机软件设定。直流信号的精度达到满量程的0.1%,输出的矩形波边沿时间小于1μs。     

基于FPGA 与Modbus 的便携式信号源设计

针对便携式、小型化与低功耗的需求,采用可编程逻辑器件FPGA 作为主控制器,设计一款便携式双通 道信号源。采用CORDIC 算法实现DDS 正弦信号的产生,输出2 路幅频相连续可调的正弦信号;利用智能触控屏 设计信号源的人机交互接口,对信号源参数进行配置与实时显示;触控屏与FPGA 之间采用Modbus RTU 协议进行 通信。实际测试结果表明：该信号源输出的正弦信号频率稳定性好,相位、幅值调节准确性好,能够满足测试设备 的需求。     

基于CPCI 总线的运载火箭脉冲信号多路采集卡

根据运载火箭地面测试的特点与要求,设计了一种运载火箭多路脉冲信号采集卡。采集卡采用FPGA芯片内计数器的方式实时采集多路脉冲信号,并利用PCI9054芯片将采集后的数据通过CPCI总线传输至上位机。采集卡经过试验,结果表明,该设计方案满足要求。与当前运载火箭脉冲信号地面测试设备相比,该采集卡具有体积小、集成度高、可靠性高和占用资源少等优点。     

基于数据选择的引信测试回波信号高精度延时

针对实验室无线电引信测试系统回波信号延时精度低的问题,基于FPGA平台,提出通过数据存储和数据选择方式来实现引信测试系统回波信号高精度延时。该方法利用自行编写的算法控制粗延时单元中的数据存储和精延时单元中的数据选择方式进行实现,在满足延时要求的基础上,有效提高了引信测试系统回波信号的延时精度。实验结果表明,本文提出的粗延时单元设计方案能够满足引信测试系统回波信号的延时需求,精延时单元设计方案能够将延时精度从FPGA时钟周期的4ns提升到1ns,意味着引信定距测试精度从0.6m提升到0.15m,测试精度提升到了一个更高的水平。     

基于异步时钟的多片门阵列并行采集模块

针对测控系统中单一FPGA的IO口不足,无法满足高采样率,上百路通道并行采集情况,提出了基于异步FIFO(先入先出队列)存储的多片FPGA大规模并行信号采集模块。该模块通过将多片FPGA采集数字信号的高低状态存储在内建FIFO里,然后将数据编帧存储在FLASH中,通过USB接口与上位机连接。仿真表明:该模块可采集400路数学信号,结构灵活、控制简单、可靠性较高,数据采集通道可根据需要进行扩展。     

一种基于DSP+FPGA 的多路串口和以太网通信系统

为满足以太网、CAN 总线和多路串口通信的需求,设计一种基于DSP+FPGA 的多路串口和以太网通信 系统。介绍基于DSP+FPGA 多路串口及以太网通信系统组成和工作原理,分别对DSP 电路、FPGA 电路、电源电路 的组成结构进行说明,对系统软件的功能进行阐述。应用结果表明：该通信系统具有运行稳定、性能可靠等优点, 可满足项目研制的需求。     

基于FPGA的等精度测频模块的研究与实现

频率测量一般是通过对被测信号和标准信号计数实现,因此量化误差是引起测量误差的主要原因.在比较分析周期测频、直接测频和等精度测频的误差后,给出了一个基于FPGA等精度测频模块的Verilog HDL实现.较之单片机实现,它具有抗干扰性强,工作稳定可靠等特点.     

基于现场可编程门阵列的脉冲激光引信高精度实时定距技术研究

采用电子计数法实现脉冲激光引信定距的本质是测量发射脉冲和目标反射回波脉冲的时间差。为实现脉冲激光引信的精确定距，在分析电子计数法时间测量的原理和误差因素基础上，给出了脉冲激光引信高精度实时定距的原理框图，用Ahera公司Cyclone系列的FPGA芯片实现了时间测量模块，其高速计数器的工作频率达到800MHz，满足脉冲激光引信的精度和实时性要求。在QuartusⅡ软件中进行了后仿真，得到了满意的结果。     

武器装填控制的智能化测试系统设计

武器装填控制测试系统由PLC主控机,数据实时采集与逻辑分析,多路信号转换与功能判断等模块组成.系统软件包括主程序、子程序、显示程序.PLC切换巡回检测点,分析采集信号、建立故障模式.通过多路信号转换、开关量识别,模拟量实际值与系统允许极限值比较,及输入、间隔定时器和高速计数器等中断处理,实现故障诊断.     

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.     

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.     

Method for Measuring Velocity of Warhead Fragments Based on Photoelectric Detection

For measuring velocity and impacting position of single fragment of warhead, a non-contact measuring method is proposed, in which a six-light-screen array, a position indicator, a multi-channel chronograph and a computer are used.The principle of measurement is described. The key device of the system is a light screen array sensor which consists of six light screens allocated with certain geometrical parameters. When the fragment flies through the light screen array, the time of passing through each of the screens is recorded by the multi-channel chronograph. According to the time data and the geometrical parameters of the array, the velocity vector and the location of the fragment can be calculated immediately. The presented method can be used to locate the fragment and to measure the real velocity on its flying direction. It can also be used to measure the velocity of a fragment swarm after the system is engineered further.     

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。     

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.     

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.     

Influence of Installing Error on the Surface Shape Precision of the Axial Symmetry Aspheric Workpiece in Lapping

A method to calculate the surface shape error, which is caused by the installing error between the workpiece and the lapping tool in the process of form lapping, is proposed. The mathematical model which the installing translation error influences on the workpiece surface shape error is established. The changing rule of the error is simulated through the calculating example of the paraboloid workpiece. The results indicate that the surface shape error of the workpiece is increasing with the increase of the installing translation error, it is also increasing gradually along the center point of the curve surface to the edge, and the influence is severer to the curve surface with great curvature than that of the small curvature when the translation error is the same.