基于PLC的污水处理控制系统的设计

本文介绍的污水处理控制系统,通过采用计算机作为上位机实现管理和监控,PLC作为下位机实现电机的控制,并使各PLC均可与PC联网通信,从而实现了远程集中控制.该系统已在深圳某商业银行大厦中使用,整个系统运行可靠,达到并满足设计的目的和要求.     

高效污水处理工艺智能化控制系统的设计

智能化污水处理系统从高密度沉淀污水处理工艺流程出发,设计PLC控制器与现场总线相结合,建立了具备集中控制和现场就地控制相结合的智能化污水处理系统,并且通过上位机监控实现污水处理工艺、设备的全面监测,同时对污水处理的工艺数据进行处理,最终实现污水长期高效智能化处理的要求.     

PROFIBUS-DP高速现场数据通信网络的组建

介绍了PROFIBUS现场总线技术的特点并组建了PROFIBUS-DP高速数据通信网络。讨论了该网络的组态、STEP7程序的编制以及现场设备GSD文件的建立方法。分析了网络数据传输的实时性与可靠性，并采用组态软件MCGS实现了上位机对PROFIBUS-DP网络的实时监控。     

HostLink与PROFIBUS的系统集成研究

设计了PLC物流控制系统，实现了PLC控制系统之间的HostLink网络通信，采用Visual Basic开发了上位机HostLink网络监控系统。PROFIBUS现场总线系统在WinCC环境下通过动态数据交换DDE方式实现了与HostLink网络的异构网络系统集成。     

基于PLC和MCGS的换热站监控系统

本文以某学校换热站为例,运用PLC和MCGS设计了一套换热站监控系统.本控制系统实行两级监控,底层系统采用PLC监控,实时采集现场数据,上位机监控界面运用组态软件MCGS进行搭建,通过PLC和上位机之间的通讯连接,可以在上位机上实时监控供热工况,并根据现场情况及时调节,系统还实现了报警功能,提高了换热站控制的自动化程度,降低了运行成本,提高了可靠性.     

基于LabVIEW的电梯远程监控系统

为保障电梯的安全运行,提高电梯运行的安全可靠性,降低成本,提高监控效果,提出了一种基于LabVIEW的电梯远程监控的设计方案。系统拟采用PLC和上位机监控实现对电梯的控制,PLC作为下位机实现对设备的直接控制,上位机负责设备工作状态监控以及各种网络的通讯功能。经过试验验证：该系统可以对电梯系统运行的各个参数进行监控,并实现参数数据的储存和输出以方便电梯的检测和维修,同时具有很高的稳定性和实时性,能够满足监控系统的需要。     

基于Modbus协议的智能脱缆钩监控系统

针对港口码头对船舶靠岸作业的远程监控和智能化控制发展趋势,设计了一种由远程上位机及现场PLC控制系统组成的智能脱缆钩监控系统,系统通过现场PLC实现对外部传感器信号的采集处理及显示,同时PLC将处理后的信号通过Modbus传给上位机,并接收上位机发送的控制指令,实现正常工况下的远程监控脱缆,以及紧急情况下的自动脱缆,有效提高了船舶靠岸作业的稳定性和可靠性。     

基于S7-300PLC的煤制油尾气制氢装置控制系统设计

针对煤制油尾气制氢装置系统中温度、压力控制较复杂的情况,设计开发了基于S7-300PLC的控制系统。在该系统中,PLC通过PROFIBUS-DP通讯协议和模糊PID控制方法实现空压机的变频调速以保证尾气制氢装置反应温度的稳定;应用WinCC组态软件实现上位机对反应过程的实时监控和远程控制;利用SQL Server 2005软件实现数据的存储和编制报表。     

多层升降横移立体停车库计算机监控系统研究

简述了多层升降横移立体停车库基本组成和监控方案,介绍了监控系统的基本功能以及PLC监控系统。通过上位机和PLC构建的网络系统,实现了立体车库计算机实时监控。     

PLC恒压供水上位机控制系统的研究

本系统采用VB6.0开发软件,实现西门子S7-200系列PLC与上位机之间的串行通信,提高PLC控制系统的实时监控性,完善控制系统的控制功能。通过VB6.0提供的串行通信ActiveX控件MSComm,采用自由口通信协议实现PLC与上位机之间的通信,使上位机能够获取相关实验数据进行存储和处理。本系统设计应用于恒压供水系统,对水泵的运行情况进行监控。     

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...     

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.     

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。     

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。     

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。     

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.     

交通荷载作用下桥梁结构参数识别方法

应用动力节点加载法,将作用在桥梁上的交通荷载转化为等效节点荷载,再用两步构造法识别结构物理参数.第1步,用Newmark-β方法变换结构运动方程,并用结构的加速度响应求得变换空间内的位移、速度和加速度响应;第2步,基于最小二乘原理,构造出变换空间内求解结构参数的递推式,进行结构物理参数识别.数值模拟结果表明,在交通荷载作用下,该方法能够快速、准确地进行桥梁结构参数识别.     

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.     

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.