Assessment of Metro Signalling System Resilience

There is high failure rate in signalling system, any signalling failure may have influence on system capacity. The concept of resilience is introduced to reflect the change of system capacity in case of failure and defined as the ability of system to maintain capacity in degraded mode and recover from disruptions. In this work, in order to quantify the signalling system resilience, three system performance indexes are formulated and calculated by the train tracking model. By comparison, the train tracking interval is selected as the performance index. With the index, resilience in different disruption scenarios are measured, the results show system resilience is closely related to fault types. In addition, when the primary mode of signalling system fails, the system resilience varies greatly with different backup modes, it is proved that optimize the design of backup modes is helpful to improve the system resilience.