PLC控制系统故障检测方法与应用

结合研究ＰＬＣ系统的实例,提出并讨论了ＰＬＣ控制系统故障检测的多种方法,可适用于ＰＬＣ系统故障检测。     

PLC在潜水泵电性能检测系统中应用

针对潜水泵电性能检测系统,介绍其整体的硬件结构、原理以及关键技术,阐述ＰＬＣ在该系统中的作用和ＰＬＣ的软件结构。     

PLC在潜水泵电性能检测系统中的应用

针对潜水泵电性能检测系统，介绍其整体的硬件结构，原理以及关键技术，阐述了ＰＬＣ在该系统的中的作用和ＰＬＣ的软件结构。     

PLC在外圆磨床在线检测自动控制中的应用

介绍了外圆磨削在线检测自动控制过程中,ＰＬＣ的控制功能以及ＰＬＣ与数控系统中Ｉ／Ｏ接口的连接及应用,并介绍了该数控系统的判别ＰＬＣ信号的方法。     

PLC与IPC在机电系统中的应用

本文探讨了ＰＬＣ与ＩＰＣ之间的关系,讨论了ＰＬＣ与ＩＰＣ的特点及其在机电系统中的分工协作,重点论述ＰＬＣ与ＩＰＣ之间的通信。     

PLC在机电设备故障诊断中的应用研究

分析ＰＬＣ对机电设备故障的诊断原理和它在故障诊断系统中的作用,利用ＰＬＣ和计算机构成的诊断系统实现了故障诊断的智能化。充分利用机电设备控制系统中ＰＬＣ的硬件资源,可简化诊断系统的硬件设计。     

用中文Word97绘制PLC梯形图

随着自动化水平的不断提高，可编程控制器的应用越来越普遍，需绘制ＰＬＣ梯形图越来越多。绘制ＰＬＣ梯形图要做大量重复性的工作，并且一旦要修改，则需重新绘制。设计速度慢、工作效率低。计算机的广泛应用，Ｗｏｒｄ９７亦越来越为人民熟知。利用 Ｗｒｒｄ９７的强大功能不仅可以处理各种文档，而且能够利用 Ｗｏｒｄ ９７的图形处理功能绘制 ＰＬＣ梯形图，具体做法如下。１ 建立ＰＬＣ元器件符号库 首先打开 Ｗｏｒｄ９７选择“文件＼新建──空文档”。然后选择工具栏中“绘图”选项，根据不同型号ＰＬＣ的规则，将所创建的各元器件…     

IPC+PLC+MCC电站锅炉吹灰监控系统

描述了ＩＰＣ＋ＰＬＣ＋ＭＣＣ在火电锅炉吹灰监控系统中的应用。系统取消了以往锅炉模拟屏和按钮群，而由大屏幕彩色显示器动态监视吹灰工艺全过程，由软操作（薄膜密封或寻标）来控制、管理整个吹灰系统。系统解决了由于ＰＬＣ内存不够的缺点，将大量数据存放于硬盘中，而不是ＰＬＣ存储器中，本系统有１４套可任意排列组合的吹灰逻辑，每套逻辑有２５６个可任意排列组合的设备代码，运行人员可以组态１２８４５０５６种吹灰工艺，     

触摸屏与可编程控制器在制冷行业中的应用

本文介绍ＣＱＭＩ和ＰＬＣ与ＮＴ３０Ｃ触摸屏在制冷机组电气控制系统改造上的应用，包括系统中ＰＬＣ与触摸屏软硬件的设计。     

智能化抽油系统的PLC控制

介绍在智能化抽油系统中ＰＬＣ的控制，包括ＰＬＣ控制过程、控制原理、控制软件设计和硬软件接线。     

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.