Research On Hybrid Accidents Causation Model Of High-speed Railway Train Operation Control System

The High-Speed Railway Operation Control System(HS-ROCS)is the core system and key equipment of the high-speed railway,and plays a decisive role in ensuring the operational safety and transportation efficiency of high-speed trains.Once the problems occur in the high-speed railway operation control system,it will likely cause traffic disruption,even the serious consequences,such as car crash.In order to improve the safety of the system and prevent similar accidents from happening again,scientific and effective models and methods must be used to characterise and analyse the cause mechanism of the accidents.Human factor play an important role in system safety.Not only in the system operational phase,but also in system development and the operational management phases,human behaviors can affect system safety.In HS-ROCS,human and technical systems work together to protect the system.However,human is also a complex system,which is affected by many factors such as technical systems,organizational management and society.It is difficult to ensure their safety features like technical systems.Therefore,how to systematically analyse the causes of accidents based on the scope of human-machine-evrionment is a system safety problem that needs to be solved urgently.In the thesis,based on requirements of cause analysis of HS-ROCS,a hybrid accident causation model based on the System-Theoretic Accident Model and Process(STAMP)for HS-ROCS is proposed with cause analysis method.Firstly,on study of the social-technical system characteristics of HS-ROCS,a hybrid accident causation model of the system is constructed,which reflects the management influence and human-machine hybrid characteristics in the system.Then,based on the Human Factors Analysis and Classification System(HFACS)and literature information mining method,a systematic accident cause classification system(SACCS)for the hybrid accident causation model of HS-RCOS is constructed.And SACCS combining with the Analytic Hierarchy Process(AHP)forms a method for cause identification and static evaluation.Furthermore,in order to findout the relationship between causes,an extended lens model(ELM)is proposed based on system component interaction,and a Multi-Object Multi-Perceiver analysis procedure based on ELM is introduced.An accident cause impact propagation model is proposed for multiple causes concurrent,and used for quantitatively analysis the sensitivity and dynamic impact of accident cause.In this way,the hybrid accident causation model and analysis method for HS-ROCS are formed,so that causes can be more accurately and efficiently identified and evaluated.In order to ensure the reliability and validation of the method,the proposed model and method are evaluated by the Krippendorff-Alpha indicator based on expert questionnaire.The innovation of the thesis is as follows:(1)The study expand the hierarchical safety control structure in STAMP.Based on system theory and control theory,for the characteristics of HS-ROCS and management process,the hierarchical safety control structure of STAMP is expanded,with the control models for system development and operation management process,in order to present the influencing factors and influencing mechanisms in the process of system safety control,which allows the analyst to more fully understand the possible causes and ways of existence in system.(2)The study proposes a systematic accident cause classification system-SACCS.Based on HFACS and characteristics of HS-ROCS and system accidents,six types of accident causal factors including organization management,unsafe Supervisions,preconditions for unsafe acts,unsafe acts,technical system unsafe status and environmental information are constructed.Based on the characteristics of causal factors,the relationship between the causal factors of SACCS and the control loop is constructed.This part provides analysts with a comprehensive classification of causes and guide analysts to identify detailed accident causes.(3)The study proposes an extended lens model for analyzing the interaction of system components-ELM.Based on the cognitive theory lens model,an extended lens model for multi-process mapping is proposed,which is used for system component interaction analysis and identification of causal factor relationship.According to the characteristics of HS-ROCS,the use of ELM is extended to multiple correspondence analysis between "situational events" and "perceivers" to analyze multiple effects and outcomes in system component interactions.It provides analysts with an effective analysis method to avoid "Hindsight biases" and more accurate analysis of the relationship between causal factors,especially human error.(4)The study proposes an accident cause impact propagation model for multiple causes concurrent.Multi-factor concurrency is added to expend the traditional cause impact propagation model,which can more objectively simulate the actual situation caused by the system accident,giving out the propagation network initial state determination method and calculation methods for cause’s sensitivity and dynamic impact.It provides analysts with a dynamic assessment method for accident causal factors,more accurately assess the role of causal factors in the accident process and the dynamic process of accident formation,providing a basis for accident detection and early warning.The thesis takes "7.23" Yong-Wen Railwya accident as an example,and uses the hybrid accident causation model and analysis method established in this paper to find out the causes of the accident,and obtains the network of the causes.Then,the causes are evaluated in static and dynamic aspects,and the sensitivity and dynamic impact of the causes to the accident are obtained.