A Security Risk Assessment Method Based on Improved FTA-IAHP for Train Position System

Abstract

The positioning system based on satellite navigation can meet the requirements of CTCS-4 train control, improve the transportation efficiency, reduce the operation and maintenance costs, which is the trend of train positioning system in the future, and the security risk assessment is of great significance to the future application of this system. In this paper, combined with the self-developed train positioning system based on satellite navigation, and an improved fault tree-interval analytic hierarchy process (FTA-IAHP) method for evaluating the safety risk of train positioning system is proposed. Firstly, a security risk assessment model based on FTA-IAHP is established by combining FTA and IAHP. Secondly, two judgment matrices are constructed by using the basic events and structural importance based on FTA, and the IAHP model based on expert scoring, the difference between FTA and IAHP is adjusted by combining the weighting factor. The new method of trial of weighting can determine the degree of each factor in the system fault. This method has great significance to the safety design and protection of the new train positioning system based on satellite navigation.