大型电厂引进型凝结水精处理系统的控制及应用

介绍凝结水精处理的工艺流程和控制原理、控制系统的总体设计,分析对引进型凝结水精处理“锥体分离和再生装置”的控制系统的消化和吸收,该系统是一个典型的由PLC完成控制功能,工业PC机完成监视与人机交互任务的分散式控制系统。     

高速公路照明用集散控制系统通信网研究

开发了一套功能较完善的高速公路照明用智能集散监控系统，提出了由Internet-Ethernet-RS485光纤网三层网络构建系统的网络通信方案。针对下位机采用基于RS485通信协议的可编程控制器（PLC），分析了联网拓展的可行性，构建了新拓展的PLC RS485网络通信系统，使PLC网络通信系统可同时接入多达256台的PLC。试验运行结果表明：系统性能稳定，实现了高速公路照明系统的远距离集中智能监控。     

涡旋压缩机组控制系统的研究

采用PLC、变频器和上位PC机实现了涡旋压缩机组的全自动控制系统，应用PLC和变频器联合控制涡旋压缩机组。实现了涡旋压缩机组流量在一定范围内的动态变化。利用VB的通信控件MSCcomm开发的通信软件。实现了上位PC机与涡旋压缩机组控制单元之间的串口通信．通过可视化控制系统软件直接控制涡旋压缩机组实验系统。实现了智能化的控制，可以很好的掌握机组的运行状况。     

高压气淬真空炉控制系统的改造与应用

对HVQ系列热处理真空炉的控制系统进行局部硬件改造,分析并提出从PLC控制向计算机控制转化的硬件改造思路和软件设计过程,成功地实现了真空炉的计算机监测与控制。     

温控箱远程监控系统软件设计

某公司设备分散分布在不同的区域,距离较远,环境干扰严重,且设备的控制系统种类繁多。本系统通过读写各类温控箱的可编程控制器,实现对各类温控箱运行状态和数据的远程集中监控与记录。要求可靠地实现设备的联网监控,且不能影响原系统的运行。介绍了以C#作为编程语言的系统软件设计,采用串口通信进行数据传输并保存在数据库中,实现了基本功能,且界面友好,运行稳定。     

PLC和MCGS在流化焚烧炉控制系统中的应用

流化焚烧炉自动控制系统采用S7-300PLC,系统中6台变频器与PLC之间采用PROFIBUS总线协议方式通讯,上位机采用MCGS工控组态软件完成工艺流程及控制参数的显示,实现生产监控和管理等功能.实践证明该系统运行准确,取得了较好的应用效果.     

Using a principal components analysis for developing a robust design of electron beam welding

This paper presents the application of principal components analysis for Taguchi orthogonal experiments to develop a robust electron beam welding treatment (EBWT) process with high efficiency multiple performance characteristics (MPCs). In this study, the principal components analysis (PCA) design incorporating the correlation matrix of tested trials is employed. In the first step, the MPCs are reduced to two independent components using PCA. Both components accounted for 98.8% of the total variance. The first principal component (PC), which refers to the integrated hardening capability index of the EBWT process, accounts for 70.7% of the total variation. The remaining 28.1% were contributed by the second PC, which can be interpreted as the penetration capability index. In the second step, we identify the most important PC loading vectors using PCA, and estimate the importance of the PCs. By using PCA, relationships between different MPCs can be investigated and the most important factors for the variance of the EBWT process can be identified. The experimental results show that redundant information could be eliminated by using principal components in conjunction with Taguchi’s orthogonal array experiments. This proposed approach is simple, effective, and efficient for developing a robust and high-efficiency EBWT process of high quality. In this study, the MPCs in the EBWT process are successfully optimized.     

Using a principal components analysis for developing a robust design of electron beam welding

This paper presents the application of principal components analysis for Taguchi orthogonal experiments to develop a robust electron beam welding treatment (EBWT) process with high efficiency multiple performance characteristics (MPCs). In this study, the principal components analysis (PCA) design incorporating the correlation matrix of tested trials is employed. In the first step, the MPCs are reduced to two independent components using PCA. Both components accounted for 98.8% of the total variance. The first principal component (PC), which refers to the integrated hardening capability index of the EBWT process, accounts for 70.7% of the total variation. The remaining 28.1% were contributed by the second PC, which can be interpreted as the penetration capability index. In the second step, we identify the most important PC loading vectors using PCA, and estimate the importance of the PCs. By using PCA, relationships between different MPCs can be investigated and the most important factors for the variance of the EBWT process can be identified. The experimental results show that redundant information could be eliminated by using principal components in conjunction with Taguchi’s orthogonal array experiments. This proposed approach is simple, effective, and efficient for developing a robust and high-efficiency EBWT process of high quality. In this study, the MPCs in the EBWT process are successfully optimized .     

PC机与PLC通信延迟研究

基于PC机与PLC的通信原理,分析了PC机与PLC通信延迟产生的过程,设计出了PC机与PLC通信及确定通信延迟程序,提出了减小通信延迟以提高通信实时性的方法,最后通过实验验证了这些方法的可行性。     

精密箱体柔性制造系统网络通信的实现

基于昆机FMS1600精密箱体类柔性制造系统的系统集成控制解决方案,介绍了FMS系统网络通信结构、设备组态及通信方式,解决了PROFIBUS现场总线与企业生产计划管理层集成不足的问题.采用PROFIBUS -DP现场总线和工业以太网双层网络结构,组成通信与控制紧密结合、控制与管理一体化的FMS控制系统,该系统经实际应用,实现了FMS全自动集成控制功能,取得了良好的经济效益.     

Towards an Integration of Process Planning and Production Planning and Control for Flexible Manufacturing Systems

This introduction article attempts to present some major issues relating to the integration of process planning and production planning and control (PPC) for flexible manufacturing systems (FMSs). It shows that the performance of an FMS can be significantly improved and FMS capabilities more effectively utilized by integrating process planning and PPC functions. The various types of flexibility to be planned and provided for in process planning and manufacturing are summarized in the article, as well as emerging conceptual frameworks for integration, along with their implementation requirements and problems. Distinctive elements that differentiate these frameworks, such as the extent of integration of process planning and PPC activities, number of alternative process plans, and the time at which numerical control programs are generated, are discussed, followed by a brief summary of the articles compiled for this special issue.     

Design and implementation of Web-based diagnosis and management system for an FMS

Given the rise in competition within the global marketplace, the paradigm for manufacturing has changed dramatically. While downstream activities have become the focal point for global competitors, manufacturing remains at the root of a firm’s competitive edge. To remain competitive, firms are progressively shifting their manufacturing operations to overseas markets. Foreign markets offer a host of advantages to manufacturers but one of the obvious key advantages is cheaper labor. Even in industries where the required labor-to-capital input ratio is relatively low within the production process, lower labor costs allow the production of more competitively priced products. The emergence of this paradigm, however, has led to a number of managerial problems. Operating a manufacturing facility overseas creates difficulties for management both in the area of personnel and resource allocation. In this project we developed a Web-based remote control platform using digital cameras, a PLC controller and a PC-based Visual Basic human-machine interface (HMI) to create a flexible manufacturing system (FMS). An FMS can be easily controlled and monitored through an Internet-based PLC-control system using a PC-based HMI platform. From remote locations, this platform enables management to effectively monitor, control and diagnose a manufacturing process via the Internet.     

PLC实验监控系统的开发与设计

研究与开发了以三菱FXON系列PLC作为下位机。科教仪器实验台为被控对象。计算机（PC）作为上位监控机的PLC实验系统。运用工控组态软件开发出能够实现对下位机进行监督与控制,对PLC设备进行管理的应用程序。运行结果表明系统不仅能稳定工作。便于操作与维护。且具有生动形象的动画界面,有实时显示及报警功能。有一定的应用参考价值。     

采油套管自动生产线PLC控制系统

简述采油套管自动线的工作流程,利用多层网络使多个PLC之间、PLC与上位机之间及上位机与各设备之间相联,实现工作过程的实时监控和生产数据的实时管理.     

Production planning of a flexible manufacturing system in a material requirements planning environment

Early flexible manufacturing system (FMS) production planning models exhibited a variety of planning objectives; typically, these objectives were independent of the overall production environment. More recently, some researchers have proposed hierarchical production planning and scheduling models for FMS. In this article, we examine production planning of FMS in a material requirements planning (MRP) environment. We propose a hierarchical structure that integrates FMS production planning into a closed-loop MRP system. This structure gives rise to the FMS/MRP rough-cut capacity planning (FMRCP) problem, the FMS/MRP grouping and loading (FMGL) problem, and the FMS/MRP detailed scheduling problem.We examine the FMRCP and FMGL problems in detail and present mathematical programming models for each of these problems. In particular, the FMRCP problem is modeled as a generalized assignment problem (GAP), and a GAP-based heuristic procedure is defined for the problem. We define a two-phase heuristic for the FMGL problem and present computational experience with both heuristics. The FMRCP heuristic is shown to solve problems that exhibit a dependent-demand relation within the FMS and with FMS capacity utilization as high as 99 percent. The FMGL heuristic requires very little CPU time and obtains solutions to the test problems that are on average within 1.5 percent of a theoretical lower bound.This FMS/MRP production planning framework, together with the resulting models, constitutes an important step in the integration of FMS technology with MRP production planning. The hierarchical planning mechanism directly provides for system-level MRP planning priorities to induce appropriate production planning and control objectives on the FMS while simultaneously allowing for necessary feedback from the FMS. Moreover, by demonstrating the tractability of the FMRCP and FMGL problems, this research establishes the necessary groundwork upon which to explore systemwide issues pertaining to the coordination of the hierarchical structure.     

柔性车削系统主轴控制研究

介绍了一种以机车制动盘为加工对象的STAR柔性车削系统,系统采用NC嵌入PC,结合PLC作为数控系统的硬件构架,系统主轴控制由PLC完成。详细介绍了PLC对主轴的升／降速处理与主轴准停控制,以及通过PC机与PLC的串口通信,实现PC机对系统主轴运动的间接控制与实时监控。     

对FMS50教学系统中PROFIBUS-DP通信的研究

首先对FMS50教学系统各站S7—300系列可编程序控制器软硬件进行简单介绍，主要介绍了下层控制网络中过程现在总线PROFIBUS—DP协议结构、性质特点，分析了FMS50中各站PLC之间及与上位PC机工控组态软件WinCC之间的数据通信实现方法。     

Design Guidelines for Deadlock-Handling Strategies in Flexible Manufacturing Systems

Deadlock-free operation of flexible manufacturing systems (FMSs) is an important goal of manufacturing systems control research. In this work, we develop the criteria that real-time FMS deadlock-handling strategies must satisfy. These criteria are based on a digraph representation of the FMS state space. Control policies for deadlock-free operation are characterized as partitioning cuts on this digraph. We call these structural control policies (SCPs) because, to avoid deadlock, they must guarantee certain structural properties of the subdigraph containing the empty state; namely, that it is strongly connected. A policy providing this guarantee is referred to as correct. Furthermore, an SCP must be configurable and scalable; that is, its correctness must not depend on configuration-specific system characteristics and it must remain computationally tractable as the FMS grows in size. Finally, an SCP must be efficient; that is, it must not overly constrain FMS operation. We formally develop and define these criteria, formulate guidelines for developing policies satisfying these criteria, and then provide an example SCP development using these guidelines. Finally, we present an SCP that guarantees deadlock-free buffer space allocation for FMSs with no route restrictions.     

基于无线通讯开放式数控系统双轴同动的研究

利用PC、PLC以及无线通讯模块搭建了具有无线通讯功能的开放式数控系统的硬件平台,阐述了PC与PLC之间无线通讯的协议和实现原理。针对目前多轴联动数控插补存在的不足,提出了双轴同动新的数控插补方法,说明了双轴同动的控制原理。设计了PLC实现双轴同动的控制程序;利用Visual C++6.0开发了上位机PC机的通讯与控制软件。最后在立式铣床上进行了加工实验,实验结果表明双轴同动方法可行,在双轴同动模式下机床加工速度快,加工出来的产品表面粗糙度小。     

PLC培训的合理实现

本文通过在三菱PLC及人机界面作图软件上的应用，介绍一种利用软硬件结合的编程组态方法，充分利用现有的资源降低培训成本。