智能算法PLC与DCS通讯实现

本文RS-485总线连接通过MODBUS RTU协议转换,实现罗克韦尔PLC与上海新华DCS通讯,并通过虚拟DPU建立数据交互和组态应用关系,从而达到智能控制算法作用到DCS控制系统自动优化的目的。     

玻璃熔窑温度智能控制系统

本文针对玻璃熔窑这种复杂的工业对象提出一种智能温度控制系统.控制采用多层结构,第一层为监督结构,利用影响性能指标的玻璃液温度作为控制量;第二层为澄清部温度控制,控制策略为自校正模糊控制算法;最底层为PID控制.利用DCS实现整体温度控制.通过实际运行证明了控制方法的有效性.     

氨合成塔温度分级递阶智能控制

本文详细分析了氨合成塔的控制难点,提出了分级递阶的智能控制方案.其中,监控级实现了系统在不同负荷下的调节参数切换,并利用神经网络模型对氨产率进行预测来指导生产操作.该方案以DCS为依托,建立上层监控管理局域网,实现了对氨生产过程的智能监控与管理.     

基于OPC的温室智能控制系统接口设计与应用

该课题来源于国家科技支撑计划项目。通过OPC接口的设计,将多因子协调控制算法嵌入到DCS软件中,以实现对温室系统基于智能控制算法和DCS架构的分布式控制。文中介绍了OPC标准的技术规范,分析了自动化接口的对象模型,根据温室智能控制系统的需求对基于OPC接口的客户端软件的功能模块和通信流程进行了设计。系统的运行测试表明,开发的客户端程序运行可靠,数据读取实时性强。     

智能控制方法的选择及其应用

随着智能控制设计形式和设计方法的日益丰富以及智能控制应用的日益普及,智能控制的相关技术及其控制策略的选择变得日益重要。本文提出了设计智能控制系统时选择何种控制方式、采用何种技术及其相应控制策略所应考虑的一般方法,并结合实例,从方法上给出了各种智能控制技术及控制策略的选择方法和简单评价。     

煤矿工作面需风量预测及通风机智能控制

为达到对通风机风速控制的准确性和解决传统风速控制方式的问题，在对通风机简单概述的基础上，对工作面需风量的预测展开研究，确定需风量预测的模型；对比了传统PID控制策略、模糊算法控制策略以及T-S模糊神经控制策略的响应特性和超调量，确定采用T-S模糊神经控制策略实现通风机的智能控制，并完成了相关硬件的选型。     

浅析热电厂锅炉控制中的智能化控制技术的应用

随着科学技术的不断发展,各行各业都将自动化技术、智能技术纳入发展规划并进行现场应用,提高生产效率。我国热电技术发展较快,部分企业虽然采用DCS系统,但还存在着智能化控制水平低、当热用户负荷波动大造成的锅炉控制系统运行效率不高、热电系统运行稳定性低等问题。电厂在DCS上实现智能控制不失为一种好的方法。笔者对相关智能控制技术进行了分析与探讨,给出了相关改进方案,通过在热电厂锅炉控制中引入智能控制系统,进而实现了热电厂锅炉工作过程的精准控制,效果良好,具有较好的推广价值。     

智能控制在烟厂烟丝烘干控制系统中的应用

本文给出了烟丝烘干系统的控制策略,利用仿人智能控制实现了烟丝烘干系统的控制,给出了该控制器的详细设计。     

CS3000DCS控制系统在PTA装置的应用

随着计算机技术的不断发展，DCS控制技术得到了飞速的发展和完善。其控制策略涵盖了传统PID控制、逻辑控制、顺序控制等各种控制策略；同时使用PC机为基础的人机接口，使DCS的工程组态得到了简化，提高了工程组态效率。在辽化80万tPrA改扩建项目中采用横河公司的CENTUMCS3030系列DCS系统，完成对装置生产过程的控制，为装置的平稳运行奠定了基础。     

集散控制系统的最新技术特点与展望

集散控制系统(DCS)因其具有控制和危险分散、管理和显示集中的显著特点仍被作为当今工业过程控制领域的主要控制系统之一.该文在对DCS的基本体系结构和技术特点进行必要阐述的基础上,描述了DCS的发展现状,介绍了最新DCS的技术特点,列举了和FCS比较DCS存在的问题,最后对DCS的发展作出了包括和FCS结合,打造更加完善的综合系统;出现更多满足中小用户需求的中小型DCS;具有无线通信功能;智能控制、智能诊断等四方面的展望.     

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.     

Limits of topographic measurement by the scanning tunnelling and atomic force microscopes

Parameters describing the topographic character of a surface (height, surface wavelength, slope and curvature) can be derived from equivalent sinusoidal profiles. The response of a surface-measuring instrument may be modelled in terms of instrument parameters such as stylus radius, and scanning range and resolution. The performance of the instrument may then be mapped as a zone in amplitude-wavelength (AW) space to show the sinusoidal profiles it is capable of measuring. In a first-order analysis the STM and AFM are considered as equivalent to contact-stylus instruments with a notional stylus radius equal to the tip radius plus the gap. Comparisons between different instruments and types of instrument are readily made by mapping in AW space. The error arising from convolution of the sinusoidal profile with that of the finite tip may be quantified and plotted as contours in AW space.