Research And Implementation Of Redundant Ethernet For Integrated Control Based On High Reliability Design

Since its emergence, Ethernet technique has been applied at each field in multipleindustries by virtue of the leading technical advantage and thus becomes the mainstreamof current LAN. With the continuous improvement of Ethernet technique and thedemands widely put forward, people gradually start to apply Ethernet technique in someenvironment with relatively high reliability. The overall reliability of network systemcan be well improved through adopting Ethernet based on redundant structure. It haswide application prospect. However, Ethernet design itself does not define thecharacteristics of redundant communication. This requires to redundancy modify anddesign of Ethernet. To meet the requirement of high-reliability, the design andoptimization must be conducted in multiple aspects including network topology,transmission mode and protocol design. The design and study of redundant Ethernetwith high reliability has aroused enough attention in the industry and become a researchhotspot focused on. Based on2011task project of the Aeronautical Science Foundationof China–“study on the dual redundant Ethernet technique available for high-reliabilitycomprehensive control”, this thesis aims to design and achieve dual redundant Ethernetavailable for high-reliability comprehensive control and carry out relevant work. Themain research contents and innovation points are as follows:1. In the aspect of topological structure design for redundant Ethernet, the way ofcombining “node redundancy” and “network redundancy” is adopted; Ethernet switchesare connected in a circular way. Two network cards at the terminal node are connectedrespectively with two different Ethernet switches; thus, the topological structure of thewhole network is designed. This ensures that when one link fails, the data can still betransmitted from another link so as to improve network reliability.2. In the aspect of data structure, protocol and communication design, the formatand TCP/IP protocol of traditional Ethernet data packages are modified; the redundancyprocessing layer is added in network application layer to realize networkcommunication demand. Then, methods and technical proposals of dual redundantEthernet communication available for high-reliability comprehensive control are mainly studied. Network data transmit-receive mode and redundancy judgment method aredesigned in detail from the network transmitting terminal and receiving terminal.Besides, the redundancy transmission way is adopted so as to improve networkreliability.3. In the aspect of failure mode monitoring and failure recovery mechanism of dualredundant Ethernet communication available for high-reliability comprehensive control,aiming at the link conditions of the whole network, corresponding failure mechanismsare designed to make timely early warning for failure node or the link. In addition,corresponding link switchover can be timely made for network failure. Meanwhile,network expansion can be recognized, and network structure information can beupdated timely.4. In the aspect of realization and verification of high-reliability dual redundantEthernet, redundant Ethernet control software platform based on high-reliabilitycomprehensive control is developed. Redundant Ethernet can be controlled anddiagnosed through the software. Software design and development process are narratedin detail through specific control interface and humanized human-computer interactioninterface. Through the network platform set up in the lab, network communication andfault diagnosis testing is carried out for the software platform in combination ofcommon software testing platform so as to fully analyze the availability andperformance of high-reliability dual redundant Ethernet and the software platform underthe environment approaching the reality.