【作者】 沈志伟；

【导师】 孙优贤；

【作者基本信息】 浙江大学 ， 控制理论与控制工程， 2002， 硕士

【摘要】 工业网络经过近30年的发展，从基于模拟信号传输的DCS系统发展到数字化、智能化、全分散的现场总线系统，给工业自动化带来一场深层次的革命。但现场总线的国际标准推出缓慢，通信协议的多样性使得不同总线产品间不能直接互连、互用和互可操作，没有真正体现现场总线的开放性。随着Intranet／Internet等信息技术的飞速发展，要求企业从现场控制层到管理层能实现全面的无缝信息集成，并提供一个开放的基础构架，传统上用于办公室和商业的以太网逐渐进入了控制领域。本文根据工业控制系统的要求，结合商用以太网成熟的设计方法，给出了工业以太网设计的原则和方法；研究并讨论将传统以太网移植到工业控制领域所必须解决的实时性、快速故障探测与自恢复、网络安全等关键技术问题。 本文的主要内容包括： 1． 系统介绍了工业网络发展的主要历程，比较了工业以太网与传统工业网络，并指出了以太网应用于工业控制领域的所具有的优势极其发展的趋势。 2． 根据工业控制领域对网络支撑系统的要求，借鉴商业以太网的设计原则和方法，设计了基于分层的结构化工业以太网结构，为工业控制系统提供了一个全分布的、对等的通信平台；同时，详细说明了设计思路和原则。针对工业环境的防护要求，给出了通信设备和电缆所应遵循的参考标准。 3． 针对商用以太网本身的局限性，结合现有技术，详细讨论了采用交换、全双工通讯模式、虚拟局域网、质量服务(QoS)等技术实现工业以太网实时性的方法和途径。 4． 研究了IEEE802.1D算法收敛慢的缺陷，讨论了采用改进的基于传播顺序生成树算法实现快速故障探测与自恢复的方法，并给出了该算法的性能评估，结果表明，该算法比传统的E802.1D算法具有更快的收敛速度，可极大地提高工业以太网的可靠性和可用性。 5． 根据工业以太网的开放性特点，讨论了实现网络安全的常用技术，包括数据加密、数字签名、鉴别技术、访问控制技术等。 相信，工业以太网以其开放的特性和结构化的设计，在工业控制领域必然有很好的应用前景；而目前仍有很多关键技术有待解决，积极的研究工作将有助于工业以太网的迅速应用，并产生良好的经济效益。更多还原

【Abstract】 liithe past 30 years, industrial network has been developed from analog-signal-based DCS system to Fieldbus system which is digital and intelligentized with totally distributed structure. Fiedlbus indeed had brought a revol ~tion in industrial automation. But the international standards of fieldbus could not be carried out quickly. The diversity of communication protocols of fieldbus makes it impossible to realize interconnection and interoperation between different kind of fieldbus products. So the openness of fieldbus can not be achieved. With the rapid development of information technology such as lntranet/Internet, the ability of seamless integration between management layer and field control layer is required as well as an open infrastructure. Traditional Ethernet, which is used in office and commercial environment, has gradually entered the industrial control field. According to the requirement of industrial control system and the greatly successful design method used in commercial Ethernet, we provide the design policy and method of industrial Ethernet. The real-time attribution, fault detection and fault recovery, network security of industrial Ethernet were also discussed in this thesis.The main content of this thesis is as follows:1.Firstly, this thesis introduces the history of the development of industrial network. The advantage of application of Ethernet in industrial control field is provided with comparison to the traditional industrial network.2.%ccording to the requirement of industrial control system and the greatly successful design method used in commercial Ethernet, we design a hierarchical industrial Ethernet stnicture which provides the control system with a totally distributed and equivalent communication platform. The design policy and method of industrial Ethernet is also described in details. According to the requirement of protection against industrial environment, we put forward a reference standard about communication devices and cable.3.According to the limitation of Ethernet, we studied the technologies such as switching, full-duplex communication mode, VLAN and QoS, which are used to make the industrial Ethernet real-time.4.We studied the defect of IEEE 802.1D algorithm which has slow convergency speed. The principle of improved Propagation Order Spanning-Tree algorithm and the mechanism of quick fault detection and fault recovery were discussed as well as the evaluation of this algorithm. The result show that POST algorithm has more quick convergency speed than IEEE 802.1D, which could improve the availability and reliability of industrial Ethernet.5.According to the openness attribute, we discuss the technologies such as data encrv~tion, digital signature, authentication technology, access control, which are used to realize network security.We believe that industrial Ethernet will have a bright future of application in industrial control field. There are still some key problems need to resolve. Positive study would be helpful to push industrial Ethernet forward in application.更多还原