Guanglin Freeway's Huayingsha Tunnel Supervisory Control System And Its Performance Analysis

This thesis has been completed on the basis of the investigation of the Huayingsha Tunnel Supervisory Control System (HTSCS).At first, the principal theory about two kinds of control network ( i.e. fieldbus and industrial Ethernet ) is studied , which have become common in industrial control field in recent years . They concern individual specialities , catagory advantages , disadvantages ,applied situation, and so on .After it is set that there are more advantages about industrial Ethernet over fieldbus , a few typical protocols are studied about combination of fieldbus and industrial Ethernet. Modbus protocol is continuously analyzed, which exists in the HTSCS .And then , the contents , function , network structure and setup about HTSCS are discussed , as well as the software of the distribution terminals and executing terminals, and the communication between them.Internet and Supervisory Control Systems (SCS) are integrated in order to obtain long-hae long-haul supervisory control; the detailed scheme of replacing fieldbus with industrial Ethernet based on embedded module are given , so as to make tunnel supervisory systems really open and communication between field devices realtime.Because of the very importance of systems' performance , an individual chapter follows. The average time lag in network transfer are analyzed and calculated . The main factors which caused the average lag time about data transfer in the Token Ring Network are known , through the comparison and analysis of the computing results .The State Space Theory is used to analyze the reliability of HTSCS in detail. The Markov reliability models of HTSCS are given and in order to make calculation easy, these models are simplified . Systems' reliability can be better in three ways and the advantages and disadvantages of each way follow . Here , the certain units'stand-bys are finally selected to improve the reliability . The calculating results of the reliability and MTBF( Mean Time Between Failure ) of HTSCS show that the reliability about HTSCS is higher, which can fulfill the actual requirement .The above analysis provides a sound theoretical basis for engineering application.