【作者】 郑海东；

【导师】 蒋静坪；

【作者基本信息】 浙江大学 ， 控制理论与控制工程， 2003， 硕士

【摘要】 本文叙述了工业控制系统的发展过程，从集散式控制系统(DCS)到数字化、双向、多节点的现场总线，现场总线实现了新型全分散式结构，把控制功能彻底下放到现场，依靠现场智能设备本身便可实现基本控制功能。以太网作为一种成功的网络技术，在商用和办公化方面得到广泛应用。因为以太网的低成本、稳定以及以太网技术本身的高速发展，人们越来越希望能把这项技术应用到工业控制领域。 基于对现场总线网络协议层的分析(我们对FF基金会现场总线详细分析了网络协议体系和其系统结构)和各类现场总线所用到的媒体访问控制协议的研究来发现现场总线是如何满足工业控制网络苛刻的确定性、实时性、高可靠性的要求。由于以太网的MAC层CSMA／CD协议，无法保证确定的排队延时。但随着以太网的发展，双工通信技术、交换技术、信息优先级、容错技术、OPC技术的应用，以太网已可用到工业控制和实时通信领域。 利用第三方的远程监控软件和Pro／E 3D CAD／CAM系统的标准软件，实现了网络监控的数控加工系统。数控系统和本地计算机通过RS232接口交换数据，远程PC工作站通过网络来监控本地计算机。 建立了基于Web技术的网络计算机实时控制实验室系统，客户端用Java2的applet来实现，并嵌入了由视频服务器传送来的视频图像。此实验室系统由水位控制，炉温控制，和温湿度数据采集实验构成。服务器端由一Web服务器和一C++的服务端应用程序构成，这个应用程序用来响应客户端的Socket，和客户端建立连接，并和控制对象交换数据，算法也在其中实现。本实验已经对学生开放，并取得较好的效果。更多还原

【Abstract】 This paper depict the evolution of industrial control, from DCS to digital PCS. The PCS has realized a whole new completed distributed system, the control functions have been entire put to the industrial field. Depending on the field intelligent device, we can realize the foundational control function. Ethernet as a successful net technology has been widely used in business field. Because Ethernet’s cost is low and Ethernet develop very fast in these years, people hope to use this technology in industrial field more and more .Based the analysis to net protocol of Foundation Field Bus and the research to MAC protocol of several field bus , we find the way that the field bus satisfied with the rigorous requirement of industrial control. Ethernet’s MAC protocol is CSMA/CD so it can’t confirm the time needed by the data via the network. But as the new technology been applied to the Ethernet :full-duplex technology, switch technology, Qos, OPC etc, Ethernet has been used in industrial control and real-time data exchange.Depending on the third part software PcAnyware and Pro/Engineer 3D CAD/CAM software, we do the net control for CNC system.Between CNC and local computer exchange G code through RS232, and the remote control local computer through network.We have established network environment for computer real-time control experiment based on the Web. The Client is made up of a Java 2 applet and a video window. The video server provides visual feedback on experiment. This experiment system has three parts: water level control of triple tank apparatus, electric heater for temperature control, temperature and humidity data collection. The server is consisted of a Web server and a C++ application, the application is used to response the client’s Socket, and establish connection with the client, while this application exchanges data with the controlled device, the control method is embodied in this application too.更多还原