CAN总线物理层波形的采集与译码

CAN总线接口芯片会自动过滤掉总线上的错误帧,而测试者总是对总线上出现的错误帧以及错误帧出现的时间和位置更感兴趣。为了更好地评估CAN总线的传输性能,提出了通过对CAN总线物理层波形进行采集分析的测试方案,搭建了波形采集存储的硬件平台,能高速存储采集到的总线数据。设计了软件对采集的波形进行分析,能自动匹配总线波特率,对波形进行译码得出CAN总线上传输的数据,并能定位分析特定时间点的波形。     

基于CAN的火控光电仪数据交换网络设计

基于控制器局部网(CAN)的火控光电仪数据交换网络，采用CAN为系统各节点间的数据交换平台，通过CAN协议对通信数据块编码，扩展数据节点，设置节点筛选器，数据节点通过各自CAN控制器与总线相联，实现网络数据交换。其中，系统监控台接收并显示网络中传输的全部数据，其设计包括不同数据节点的CAN控制器，及单片机控制的CAN接口模块和基于DSPTMS320LF2407A的CAN总线接口等。     

一种ISA 总线转CAN 总线接口的实现方法

CAN总线在分布式控制系统中有着广泛的应用,而ISA是经典的工业控制总线,为实现两种总线间的通信,设计了一种ISA总线向CAN总线转换的接口电路。阐述其实现原理,提出完成时序匹配和转换需满足的条件,对CPLD内部逻辑进行分析,并给出ISA时序分析框架图。结果表明,该方法运行稳定、可靠,在实际应用中可下挂30个CAN节点,有一定的工程参考价值。     

基于DSP和FPGA的多总线通信接口设计

基于数字信号处理器(DSP)和现场可编程逻辑门阵列(FPGA)设计了一种嵌入式多总线通讯接口系统,实现了千兆以太网与1553B总线和CAN总线间的数据信息交互。DSP通过上层应用程序实现千兆以太网和1553B总线、CAN总线间的数据转换和处理。在FPGA内完成对1553B总线和CAN总线的逻辑控制和时序转换。对系统的总体方案设计、硬件构成、各模块功能的实现以及软件流程进行了设计和分析。在调试和试验过程中证实该系统通讯实时性强,性能稳定、可靠。     

基于CAN 总线的星上交互式仿真框架

为解决星上仿真系统的接口规范以及仿真交互协调的问题,建立基于CAN总线框架的交互式星上仿真系统。依照各组成部分进行建模,形成多个仿真成员,在各成员驱动程序接口之上进行二次封装,形成统一接口,再配合CAN总线仿真框架,构建星上仿真系统。设计并实现了各仿真成员之间统一的通信接口,规范了仿真流程框架,构成了各仿真成员相互交互、协调运行的基础。实验结果证明,该仿真框架传输效率高、运行稳定、适应性好,达到了预期效果。     

车载CAN FD总线终端电阻的优化研究

传统的车载控制器局域网络不能满足汽车智能化对带宽和速度的需求,CAN FD网络作为传统CAN网络的升级版,有效地提高了总线的速度和可靠性.CAN FD的接口电路的众多元器件中,终端匹配电阻对总线信号的影响最大.文章首先对CAN FD总线的通信特点进行了研究,总结出CAN FD总线与传统CAN总线的区别.其次,在应用层和物理层方面对总线网络进行了优化,确定了总线信号质量的评价指标,采用归一化与加权求和的方法将优化总线信号质量这个多目标优化问题转化成单目标优化问题,利用粒子群算法求解出最佳的总线电阻匹配方式.最后,通过Saber软件和MATLAB联合仿真的方式,验证了设计的总线电阻匹配算法可以达到整体优化总线信号质量的作用.     

基于CAN总线网络的鱼雷制导系统信息传输可靠性分析与设计

为了实现将CAN总线网络应用于鱼雷制导系统中,通过对基于CAN总线网络的鱼雷制导系统信息传输的试验验证与硬件设计,形成了在进行鱼雷制导系统CAN总线结构网络设计时,应该从制导系统CAN总线协议规划及报文制定、供电体制规划、CAN总线终端阻抗匹配及输入输出隔离设计以及电磁环境要求等方面来提高CAN总线数据传输可靠性的经验和设计方法.初步试验表明,CAN总线网络技术可以满足鱼雷电子系统的通信需求.     

弹上CAN总线网络设计仿真与实时性分析

弹上CAN总线通信对实时性有较高要求。基于某型空地导弹控制系统,设计了弹上CAN总线网络。串行发送延时、硬件接口延时及媒体访问延时是网络延迟的主要原因。采用非抢占优先级的M/M/1排队论模型研究了该总线系统的介质访问延时,并在该弹上总线网络上进行了仿真验证。结果表明:800k和1000k波特率下该总线网络正常通信,最大延迟时间分别为508μs和292μs,远小于最低10ms的数据发送周期,满足实时性要求。     

基于AduC812的CAN总线接口设计

CAN总线接口设计以AduC812为控制核心,将其地址数据总线与CAN控制器相连,经光电隔离把地址/数据发送到CAN收发器后,可在CAN总线上的传输.AduC812和CAN控制器的复位由复位芯片分别控制.CAN驱动程序采用CAN 2.0A协议.通过设置812 IE寄存器、初始化CAN控制器并将其置为复位模式、配置控制器寄存器并置为正常工作模式等,可实现CAN通讯.     

基于C8051F060单片机SPI接口的CAN中继器设计

设计了一种CAN中继器,可以对两个CAN子网进行数据转发.本中继器采用两个C8051F060单片机内置CAN控制器连接不同的子网,两个C8051F060通过SPI接口进行数据传输.测试结果表明:CAN总线中继器能在最高CAN通信波特率条件下正常通信,也能起到扩展通信距离的作用,同时能以较高的效率实现高低速CAN子网的正常数据转发,经中继器后的通信延时很小,符合系统要求.     

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.     

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.     

Experimental Research on Output Performances of Giant Magnetostrictive Actuator

The paper introduces the performances of magnetostrictive actuators and its applications, discusses the design methods for the structure and internal magnetic circuit of a giant magnetostrictive actuator, and makes tests on the output displacement and force characteristics for an actuator using homemade magnetostrictive material. The experimental result shows that the actuator has satisfactory output precisions and ranges in transient and stable states, and can be used in lowfrequency vibration control system of precise equipment.     

Robust Graded Sliding Mode Tracking Control for Low Speed Spinning Ballistic Missiles

The nonlinear dynamic model of spinning ballistic missiles is established during the first boosting phase of the missile. Based on the conventional backstepping sliding mode control and the assumption of a two time-scale separation of missile dynamics, a graded sliding mode controller is designed with two sub-sliding surfaces which have invariability to external disturbances and parameter perturbations, and a matrix which comprises three first order low pass filters is introduced to prevent ＂explosion of terms＂. Owing to the upper bounds of the uncertainties are difficult to obtain in advance, adaptive laws are introduced to estimate the values of the uncertainties in real-time. Eventually, the numerical simulation results given to show the proposed controller can ensure the steady flight of missiles.