Research Of Reliability Evaluation Method Of Subway Mian Control System Based On FTA And Software Development

With the development of social economy and the improvement of living standard, government, society and people pay more attention to the common safety. As the vitals of city track traffic, the safe and stable operation of subway are very important. Subway Main Control System is the substantial guarantee of the reliable operation of subway system, so the research of the reliability evaluation method and the analysis of the reliability of Subway Main Control System have significant academic and applied value. They're helpful to the design, maintenance and perfection of Subway Main Control System.The Subway Main Control System is a large distributed data acquiring and monitoring system. It controls almost all equipments of subway. Though highly integration and interlinkage, system operation could be managed concentratively in order to realize source sharing, communication, and modern operation and management. Before analysising the system reliability, we shoud clearly know the structure and function of the system. So the paper makes large research and study on the composing of the Subway Main Control System first. Based on this, we compare and try 4 common methods, and at last put forward fault tree as the reliability method of the Subway Main Control System.Using fault tree method, We can get the system failure rate, the contribution of system equipment/subsystem to the system failure quantificationally. We also can get all failure combinations of the system and all combinations which can keep the system running qualitatively. This paper uses Binary Decision Digraph (BDD) to calculate fault tree. First, we use line search method to divide the whole fault tree into several subtrees, and then use its expressions to transform the subtrees to BDD one by one. At last integrating the subtrees' results can get the primary fault tree anlysis results.A embryo software of Reliability Analysis and Data Management of Subway Main Control System has been presented, so that the users can evaluate the system reliability conveniently and manage reliability data efficiently. As introducing BDD arithmetic, this software includes the following functions: computer assistant fault tree modeling function, system auto reliability analysis function and system reliability data statistic management function. Fault tree model of any system and analysis result utilizing analysis function of the software can be gained for users which avoid complex account. Finally, applying the software to station monitoring system and center monitoring system proves that fault tree analysis method can analyse reliability of the Subway Main Control System and this software is doable.