Research On Safety And Reliability Analysis Of Regional Computer Interlocking System

Computer interlocking system is the key for ensuring safety and reliability operation of the train signal equipment. With the development of the railway networking, intelligible and integrating, regional computer interlocking is developing rapidly. Compared with traditional station interlocking, regional computer interlocking has the advantages that equipment can be placed centrally, maintenance easily, in addition, operating costs is also reduced, efficiency is increased with fewer staffs and improving the efficiency of transportation. Therefore, the research on safety and reliability of the regional computer interlocking system is extremely helpful to provide theoretical guidance for rebuilding line and the new line. What’s more, the research can be guidance for the design and maintenance of regional computer interlocking system, and has positive practical significance for the promotion of the development of regional interlocking in our country.Based on the in-depth analysis of regional computer interlocking system structure and function, considering the influence of the common cause failure, the diagnostic coverage and online maintenance rate, the Markov models of two and three regional computer interlocking system were built. And then, using the matrix iterative method to solve the Markov model, the indexes of the system safety and reliability, including probability of falling safety(PFS),probability of falling danger(PFD) and mean time to failure(MTTF) were obtained. For the problem of the insufficient of traditional Markov analysis methods to analyze dynamic failure problems of computer interlocking system, thesis puts forward dynamic fault tree(DFT)method to analyze its safety and reliability, by using the method of probabilistic approximation, the relevant safety indexes of the system were calculated. The relatively complete DFT model was established in order to solve the complex solving process of Markov model, and the same solution of system safety index was got, the results of which was compared with the results of Markov process.The results of comparison show that the regional computer interlocking system has high safety and reliability, and the indexes of the two methods are very close to each other. The DFT method is not only reduces the complexity of modeling and computation, but also meets the requirement of real-time. This provides a new way of thinking for the complex dynamic redundancy system security and reliability analysis.