矩形波导中微波功率自动测量系统

采用Lab VIEW软件开发平台,设计了一套对微波信号的功率进行自动采集与处理的测量系统。该系统自动测量程度高,测量结果准确,效果非常理想,符合现代自动测量技术理念。     

一种基于FPGA的信号采集系统自动重启方法的分析

基于FPGA的信号采集模件因其高时钟频率、内部延时小、时序简便、精确控制,编程配置灵活等优点,被广泛应用于工业测量领域。本文就如何提高基于FPGA的信号采集系统的安全性进行了详细的分析,提出了一种方法即基于FPGA的自动复位重启电路,解决了目前基于FPGA开发的模件因各种错误而导致运行卡死的情况,大大提高了采集系统运行的可靠性与安全性。     

基于DSP和FPGA非圆齿轮测量仪数据采集系统的设计

用极坐标法测量原理对非圆齿轮进行高效率、连续自动跟踪测量.设计了基于DSP和FPGA的非圆齿轮测量仪的数据采集系统,系统要求采集2路光栅信号、1路模拟信号,以位置模式控制电机的运动,采用串口通讯的方式和计算机进行通讯.采用DSP+FPGA结构的信号处理系统显示出其优越性.     

曲轴在线综合测量机的原理及组成

介绍了一种汽车曲轴在线多参数综合测量机,该机采用气电转换技术、信号调理电路及多路信号采集等方法,可自动完成曲轴终检工序47个参数的综合测量,其准确度误差<2μm。测量机所具有的专用测量系统与控制软件技术,实现了自动识别和处理零件的几何特征(如键槽、油孔等),具有自动调频、自动调零与校准、故障自检等功能。     

液位自动化测量系统设计

设计了自动化检测系统。利用电容传感器面积变化,对液位(水位,油位)进行自动测量,详细介绍了传感器的基本原理,信号的转换过程以及采集系统的工作原理。     

SCTF通风机性能自动测试系统的研制

SCTF通风机性能自动测试系统是按GB/T 1236-2000标准要求研制,能进行标准中规定的四大类试验测试。该系统选用符合标准规定的各种相应传感器通过自主设计的信号采集流程,实现现场试验参数的实时采集,并由串口送入计算机,通过系统计算机中的风机自动测试软件,实现被测风机自动开启、转速自动调节和阀门自动控制,完成测量参数自动采集、自动处理、自动储存、自动显示、自动绘图等功能,并自动将性能曲线插入可供打印的Office格式的试验报告。参照相关标准对SCTF通风机性能自动测试系统的仪器设备进行了B类标准不确定度的评定。     

基于热电偶的智能测温系统的设计

论述了一个采用K型热电偶作为测量元件的炉温测量系统,其中温度传感器将采集到的微弱的信号经过放大器LM324及其相应电路放大,放大后的信号通过ADC0809模数转换芯片转换为数字信号后送入单片机进行处理,并通过显示屏LED进行实时显示。同时将测得结果与设定值比较,若测量值大于设定值系统将自动报警。     

基于虚拟仪器的转速、转矩、功率测试系统设计与研究

设计了基于虚拟仪器技术的转速、转矩、功率自动测试系统.系统采用LabVIEW语言设计,能够实现对旋转轴动力参数转速、功率的测量,并能实现数据的自动采集、保存、处理.由于该自动测试系统信号采集与信号处理相分离,其应用范围广.     

窝点接触力自动测试仪数据采集系统的设计

实现了一种用于自动测量弹性臂窝点接触力的新型测试仪.主要介绍了该仪器数据采集系统的硬件和软件设计.其中硬件电路的设计包含了信号调理电路和信号采集电路,前端使用了仪用放大器调理传感器输出的微弱信号,后端使用了AVR单片机完成AD转换和数据串行传输.上位机软件主要负责仪器的运动控制、视觉测量和数据的采集和处理.软件的数据处理部分采用了Matlab6.5与VC6混合编程来实现窝点接触力的求解.     

基于AVR单片机的智能仪表信号采集与显示系统设计

随着传感器技术的不断发展,如何更好地对信号进行处理越来越重要。根据传感器输出信号的不同,本文提出了一种以AVR单片机ATmega16为核心的信号采集与显示系统。该系统充分利用了高性能AVR单片机的片内资源及外围扩展电路,能够接收多种类型的测量信号,具有较强的在线修改和丰富的显示功能,并且采取硬件和软件双重抗干扰措施提高了测量信号的可靠性。     

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.     

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。     

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....     

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.