基于ControlNet现场总线的PLC双CPU冗余控制系统实现

阐述了在ControlNet现场总线网络环境下，采用美国罗克韦尔公司的Control Losix1756-L55双CPU的PLC控制器，以软件方式实现CPU的冗余控制。这是一种投资少、效果好的提高系统可靠性的有效手段。     

交流伺服系统的冗余控制研究

由于火炮控制系统中对交流伺服系统的高可靠性要求,提出了双CPU的冗余控制方案。基于TI公司的一款浮点型DSP,采用两片TMS320F28335为主芯片的硬件冗余方案,运用解析冗余的双CPU故障检测法判别故障并进行故障定位,实现冗余热切换,从而保证了系统工作的连续性。     

PLC中双CPU在快速锻造压机中的应用

在快速锻造压机自动控制中,采用西门子S7-400双CPU的PLC控制器,实现了双CPU协同工作,提高了系统响应速度和控制精度。     

核电站硼酸管道电加热控制柜硬冗余控制方法

管道电加热系统:通过热电偶采集现场温度信号,经PLC控制电加热器加热与不加热。此技术方案解决了长距离管道伴热通过2~3支热电偶实现温度均衡控制,以及PLC在长期工作状态下CPU可能出现问题时导致数据瘫痪的情况,而采取的冗余控制方法。     

基于VC++和OPC的冗余监控程序设计

针对泥沙输送实验台运行过程中存在的监控程序可靠性不足的问题,对西门软冗余技术、OPC技术、VC++编程技术进行了研究,对基于西门子软冗余的监控系统的下位机PLC主站与上位机监控程序之间的通信过程与特点进行了归纳,提出了一种利用OPC技术实现两台监控计算机与两个S7-300PLC站点之间进行通讯的方法。通过采用西门子的SIMATIC NET软件建立了OPC服务器,采用VC++语言编写了具有冗余功能的实验台监控程序。通过判断主/备用CPU的状态标志位,由监控程序识别当前哪个CPU是主CPU,并对主CPU内的数据进行读/写。利用故障模拟实验对监控程序的稳定性和可靠性进行了测试。研究结果表明,该程序能够实时监测实验台的各项参数,能够实现主/备系统自动切换、故障报警等功能,程序运行稳定,可靠性高。     

基于ControlNet网络的CPU冗余热备系统

以ControlLogix处理器为例,介绍了PLC冗余热备系统的工作原理.基于ControlNet网络,利用软件开发了CPU冗余热备系统,并结合对风力负载被控模型的控制实验,对其性能进行了测试和分析.     

采用小型PLC搭建冗余控制系统的研究与实践

介绍了采用小型PLC实现冗余控制方案中的硬件配置,对冗余控制系统的关键点——主从PLC的判断及切换原理进行了阐述,分析了实现冗余控制所需占用的IO点以及采用小型PLC搭建的冗余控制系统中输入输出信号的处理方法,并以OMRON PLC为例阐述了程序的实现方法,为IO点数少但需要实现冗余控制的场合提供了一种低成本的解决方案。     

基于PLC的泥沙输送实验平台冗余控制系统

为了解决泥沙输送实验平台控制系统可靠性不高的问题,采用硬冗余技术,以西门子400H PLC为控制核心,分别在CPU、通信网络和上位机等方面进行了冗余设计,并进行了组态和编程实现,建立了具有冗余和容错功能的泥沙输送实验台控制系统。同时,通过USS通信协议,实现了315 k W西门子MIDIMASTER系列变频器的控制和参数采集,并利用Y-Link组件将其融入到冗余系统中,降低了大功率变频器对控制系统的干扰,丰富了采集参数。实验结果表明,冗余控制系统具有很高的容错性能,可以有效避免因宕机、通信中断或CPU报错等故障所造成的实验平台失控现象,从而大大提高了实验平台的控制可靠性。     

新型集散控制系统控制站控制与通信功能

文中分析研究了新型集散控制系统中控制功能.研究了现场控制站的通信功能和虚拟测试功能.对现场控制站模件和可靠性进行了阐述.对现场控制单元CPU控制作用进行详细的说明.实现了容错冗余.控制站不仅可以与现场总线通信进行数据的交换.而且经过Ethernet可以实现PLC与DCS交换数据.     

编译型PLC Modbus协议的研究与实现

在编译型PLC的研发过程中,为使PLC的通信具有通用性和开放性,采用了Modbus协议。针对中断数据收发会占用大量CPU的问题,以及几种常用PLC通信方式的优缺点,通过对Modbus协议的研究,在ARM技术和操作系统的支持下,结合编译型PLC的特点,提出了一种中断组合DMA的数据收发新方法和一种多任务通信方法,实现了一种实时性较好、CPU占用量较少的适合于编译型PLC串行链路上的Modbus服务器通信。测试结果表明了程序的正确性。     

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...     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

Fifth International Summer School on Screw-Theory Based Methods in Robotics

正3-11 September,2014University of Bologna,Bologna,Italy www.summerscrews.org summerscrews2014.ing.unibo.it SUMMER 20SCREWS 14In 2014,our screw-theory school comes to the world's oldest university.In early September,Summer Screws'14 will gather six experts in the application of screw theory in robotics and up to 40 participants at the University of Bologna,Bologna,Italy.The school will teach attendees how to apply existing methods and empower them to develop new ones in their own research.The basic theoretical notions will be introduced in a rigorous manner,emphasizing examples,applications,and exercises.Scholarships are available.     

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.     

INDUSTRIAL ENGINEERING AND VISUALISATION-A PRODUCT DEVELOPMENT PERSPECTIVE

Taking the actual project of teaching and researching process for example, the relationship between the industrial engineering and product development is discussed. And use the novel visualization technology to support the industrial engineering and product development. How to use the new computer modeling and simulating technologies to support the product development and industrial engineering, is introduced especially. The support includes both domestic products and industrial systems. The visualization and computer technologies take a very important role in some system or multi-direction modeling, those technologies mentioned above can help the industrial engineers study the effect of design on the whole life circle, including the producing steps. So the engineers can avoid making the wrong decision which may cause bad effects on the whole industrial engineering.     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

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...