Reliability Research On ATP Of High Speed Railway Based On Dynamic Fault Tree

High speed railway Automatic Train Protection(ATP) system is a high speed railwayvehicle subsystem of high speed train operation control system,it is the important equipmentto ensure safe and reliable operation of high speed train.ATP system is a complex and safety-critical system,Rliability research of the system is very important to improve the system andlay down the repair strategy.With high speed railway ATP system and its the dual systemredundancy subsystem as the object of research,Through modeling to evaluate the reliabilityof the system and the influence of many factors on the system reliability are studied.High speed railway ATP system has the characteristics of complexity,maintainability,fault-tolerance and redundancy,the conventional reliability analysis methods such as the relia-bility block diagram,fault tree,Markov process,there are some deficiencies in the analysis ofits reliability.According to the drawback of traditional methods describing the dynamic failureproblem of high speed train control system,dynamic fault tree was used to analyze thereliability of the system. Firstly,The dynamic fault tree model was established by analyzingthe structure and function of the system.Secondly,using the depth-first left-most traversalalgorithm searched for the dynamic fault tree model.then the independent subtrees wereobtained.Finally,introdueeing in the reliability indexes of repairable system such as availabili-ty failure frequency,mean time to first failure,the analytic method and Markov matrix iterationmethod were adopted to solve subtrees.The hierarchical iteration method was applied toimprove dynamic fault tree analysis method to reduce the quantity of computation so that thereliability indexes could be used for reliability evaluation of high speed train controlsystem.Comparing the results of above method with the results of using the reliability blockdiagram and Markov process:the reliability of high-speed railway ATP system has higher,anddynamic fault tree analysis can describe the characteristics of redundancy and fault-toleranceof system better,the accuracy of reliability indexes is improved.Dual redundancy structure was widely adopted in the subsystem of the high speed rail-way ATP system such as security computer,the track circuit information receiving module,thebalise information transmission module.Common cause failure(CCF),fault detection,state ofrepair are important factors in affecting the reliability of the system,By markov processmethod considering the above factors,the dual system redundancy subsystem reliabilityanalysis model was established,through simulation of the model show that the increase rate ofsystem maintenance and fault detection coverage,reduce the related failure between systemcomponents is a effective method to improve system reliability.The analysis results providebasis for improving the reliable design and designating repair strategy about dual redundancysystem.