基于VXI总线的直升机驾驶仪综合自动测试系统

面向航空、航天机载设备的自动测试、故障检测与维修,应用VXI总线技术和虚拟仪器技术为某型直升机自动驾驶仪设计了综合自动测试系统。介绍了设计要求、硬件组成、软件结构和系统特点。最后说明所设计的VXI总线测试平台是一个通用型综合自动测试平台。     

XVI总线技术在航空制导武器测试系统中的应用

VXI总线技术是当今计算机测控技术发展的主流,是自动测试设备(ATE)标准化技术的核心。本文在简述自动测试系统组成及基本原理的基础上,介绍了以VXI总线技术为核心的航空制导武器自动测试系统的总体设计思路和原理,并阐述了该测试系统的功能、工作原理、硬件组成、软件组成。     

基于VXI总线的逻辑分析仪模块设计

提出了一种基于VXI总线的逻辑分析仪模块的设计原理与实现方法,介绍了深存储与快速传输以及VXI寄存器基接口的实现原理,给出了其实现方案.按照该方法设计的逻辑分析仪模块实现了大容量数据采集与快速传输.     

基于IVI模型的VXI总线任意函数发生器驱动程序的设计

VXI总线硬件平台是仪器总线和自动测试系统的优秀平台.本文介绍了基于VXI总线的虚拟仪器驱动程序的IVI模型,给出了其结构和工作原理,应用IVI模型设计了VXI总线虚拟任意函数发生器的驱动程序.该虚拟仪器驱动程序能够实现VXI总线任意函数发生器的驱动.     

航空发动机试车台热电偶测温的实现方法

本文根据某型涡轴发动机试车台的温度测试系统,详细论述了热电偶测温的工作原理,介绍了90国际温标的数学模型及线性拟合方法、VXI数据采集系统对热电偶信号的采集处理方法。该系统目前工作稳定可靠,能满足型号试验要求。     

Ⅲ型弹条淬火温度自动分选装置的研制

介绍了Ⅲ型弹条淬火温度自动分选装置的研制工序,分析了温度自动分选系统的原理,信号采集与比较、自动控制工作原理等.装置运行效果达到了设计要求.     

基于DSP技术的VXI传感器信号处理模块设计

把DSP技术应用于VXI测量仪器是今后VXI仪器设计的一个重要趋势。结合国家九五重点科技项目“自动测试系统及设备技术研究”中的三个分专题：“热电偶测温模块”、“热电阻测湿模块”、“应变片测量模块”，介绍了一种基于DSP技术的VXI传感器信号处理模块。它是一种包括了热电偶、热电阻、应变片测量在内的实时多功能测量模块，该模块建立在一种新的模块化VXI仪器平台上，可以同时进行热电偶、热电阻、应变片的测量，大大提高了仪器的通用性，为组建VXI总线自动测试系统提供了基础模块。     

VXI总线技术在空间有效载荷自动测试设备中的应用

采用VXI总线技术组建的自动测试设备包括智能接口、由VXI总线模块仪器组成的数据采集系统和以VEE为开发环境的自动测试软件.智能接口成功地解决了对测试对象提供的检测信号的相互隔离;VXI总线模块仪器的使用大大地提高了整个自动测试设备的硬件可靠性;使用VEE开发自动测试软件,降低了软件开发的复杂程度,缩短了开发周期,保证了自动测试软件可靠性.这套自动测试设备实现了对空间有效载荷的在线自动测试,为检验空间有效载荷的功能提供了可靠的依据.     

基于VXI总线的新型AWG的设计

基于VXI总线的任意波形发生器是随着计算机技术和微电子技术在测试仪器中的应用而形成和发展起来的一类新型测试仪器。任意波形发生器的价值在于它能真正产生任意波形。文中提出了一种新型的任意波形发生器结构，介绍了基于VXI总线C尺寸任意波形发生器设计的全过程，开发了VXI总线寄存器基接口、用DDS技术设计了功能电路、开发了AWG的软面板、应用控制程序和仪器驱动器，所设计的任意波形发生器的特点是：高速、模块化、方便的波形输入以及和VXI资源相结合。该任意波形发生器模块已应用于模块化雷达自动测试设备中，能提供测试系统所需要的任何波形激励信号。     

气象仪器检定自动化及数据共享平台的开发

针对目前气象部门普遍使用的传统的计量检定设备进行自动化改造,阐述了改造的整体思路,给出了各子系统的设计原理和软件流程,在Windows XP系统下采用串行通信技术实现检定数据自动采集、自动处理和自动打印检定证书,并建立检定数据库。该平台的建立,将实现检定系统的全程检定自动化,大大减轻劳动强度,减少人为误差,缩短检定时间,提高工作效率。     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

ANGULAR DISTORTION ALLOWABLE VALUE AND ASSESS METHOD OF WELD ON COKE TOWER

A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mm×28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.