基于LabVIEW的虚拟温度测控系统设计

测控系统正向虚拟仪器方向发展。基于Lab VIEW开发了虚拟温度测控系统,内部软件部分通过串接口与PC通信,外部硬件部分是通过A/D口与系统连接的数据采集卡和温度传感器,构成基于Lab VIEW的虚拟温度测控系统。通过温度感测传感器性能实验的实际应用,表明基于Lab VIEW的温度测控系统开发软件能够完成对温度的精确测控。     

基于磁电传感器的液压马达转速测控系统设计

以变转速泵控马达液压系统为平台,设计了基于磁电传感器的液压马达转速测控系统。应用虚拟仪器技术,通过Lab VIEW软件编制液压马达转速测控程序,进行了相同负载工况条件下马达转速开环、闭环PID和模糊控制对比实验研究。实验结果表明:系统转速刚度较低,在开环控制中,马达实际转速存在降落;开环、闭环PID和模糊3种控制方式中,马达转速响应都存在滞后;开环控制响应快,存在稳态误差;闭环PID和模糊控制精度高,鲁棒性好;闭环PID调整时间比开环和模糊控制长。马达转速测控系统简单、可靠,方案可行。     

基于LabVIEW的电机转速转矩测量系统设计

传统的电机性能参数测量系统一般以单片机为核心,包含用户接口、输出显示等功能,但这些产品都是以硬件为核心,使得与用户的交互和功能的修改都很不方便。现基于Lab VIEW软件平台,设计一个电机转矩转速测量系统,利用JN338转矩转速传感器检测电机驱动控制系统的转矩、转速信号,然后利用DAQ数据采集卡采集从JN338转矩转速传感器出来的转矩、转速信号,并利用Lab VIEW软件对测量的信号进行计算处理,得出实际转矩、转速大小及波形;另外,测量系统界面设计十分人性化。     

基于虚拟仪器的仓储综合监测系统

文章介绍了虚拟仪器的概念及其软件开发平台 Lab VIEW的功能与特点。运用Lab VIEW开发了用于仓储综合监测的虚拟仪器系统 ,给出了虚拟仪器技术在工业应用中的广阔的发展前景     

基于虚拟仪器的IIR数字滤波器设计研究

Lab VIEW是实验室虚拟仪器集成环境。使用它可以将数据采集分析 ,仪器控制硬件以及 PC设备整合集成 ,来建立完全符合自己特殊需求的虚拟仪器系统。文章主要介绍Lab VIEW在数字滤波器中的应用     

基于虚拟仪器的螺杆式压缩机监测系统研究

针对螺杆式压缩机的运行控制要求,采用虚拟仪器软件开发平台Lab VIEW对螺杆式压缩机进行在线监测系统的软件和硬件设计。通过监测系统以便实时掌握螺杆式压缩机运行状态和变化趋势,为实现预知维修、机组高效运行和故障诊断提供了有效保障。     

基于声信号的柴油机故障诊断应用系统研究

为了使基于声信号的柴油机故障诊断技术得到推广应用,需要研究一种能够实现柴油机声信号采集、信号处理、信号输出的系统。应用Lab VIEW作为虚拟仪器开发平台,通过MATLAB Script节点实现Lab VIEW与MATLAB的混合编程,搭建了一个实现信号采集、特征提取、故障诊断功能的柴油机故障诊断应用系统。     

基于数据采集板卡USB-4704和LabVIEW的虚拟仪器测试系统

论文介绍了一种基于研华USB-4704数据采集板卡和图形化编程软件Lab VIEW的虚拟仪器测量系统,该系统实现了对薄膜压力传感器(Flexiforce Sensors A201)调理电路中电压信号的实时采集、处理、存储,从而可以有效的测量施加在薄膜压力传感器的法向载荷。测试系统主要由薄膜压力传感器、传感器调理电路、数据采集板卡USB-4704、应用开发软件Lab VIEW组成。     

基于LabVIEW的FEAD系统动态参数测试系统研发

本测试系统是以Lab VIEW软件为开发平台,配以必要的传感器、信号调理器和数据采集卡等硬件组成的便携式发动机前端附件驱动(FEAD)系统的测试分析系统。采用图形化编程语言Lab VIEW作为开发软件,减少了测试过程中的硬件设备,实现了对FEAD系统测试信号的实时采集、处理和分析。虚拟仪器搭建的FEAD测试系统安装、扩展方便,减少了对FEAD系统的干扰,保证了测试的精度。     

基于虚拟仪器的旋转体质心测量系统

介绍了基于虚拟仪器的旋转体质心测量系统的基本组成、实现方法和功能，采用Lab—VIEW可视化的虚拟仪器系统开发平台，把传统仪器的所有功能模块集成在一台计算机中，用户可以利用虚拟仪器的软件改变其功能与规模。该系统实现了旋转体质心测量数据的自动采集，并能通过计算机进行测得数据的自动处理和分析。     

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.