Safty Analysis Of CTCS-1 On-board Equipment

With the continuous improvement of science and technology and economic strength in China,safe and efficient rail transportation has become increasingly significant.The existing railway occupies from 70 percent to 80 percent of total railway mileage and the security of signal system needs to be further improved.To meet the transformation of existing signal system,CTCS-1 train control system is of great significance to improve the safety of existing train operation.The safety analysis of CTCS-1 train control system is performed by means of effective safety analysis method to dicover the key factors and safety hazards of the system.The preventive measures are adopted to prevent the influencing factors and safety hazards in the stage of system design,which is of important value for the design,implementation,operation and tenance of Train control system.The main purpose of this paper is safty analysis of CTCS-1 on-board equipment.The main contents are listed as follows:First of all,based on the background of the major progect of China Railway Corporation,the composition and function of CTCS-1 train control system and communicated methods between subsystems were introduced.Secondly,combined with System-Theoretic Accident Model and Processes,STAMP-Based Hazard Analysis,and the characteristics of CTCS-1,a Multi-Resolution STAMP model was proposed.The model transfered the interaction and safty protection function to a process of control and feedback from each different angle.On this foundation,the study extended and formalized inappropriate behaviors,and proposed Multi-Resolution STAMP Action Relationship(MSAR).The descriptive language based on symbol was proposed over the formal definition of MSAR.Further,its corresponding safty analysis method was proposed.Hazardous events were defined and the causes of behaviors wew pinpointed by following resolution levels and association paths of inappropriate behaviors.Thirdly,an example of side-line was used to divide resolutions from the angle of function and control mode,and Multi-Resolution STAMP models were built.In addition,the paper emphasized that,in order to ensure the correctness of model and the accuracy of analysis result,modelers should have a clear understanding of hardware structure,function,interface characteristic,communication mode and protocol.Finally,under the premise of the establishment of each model,system level hazards were defined.Based on the proposed MSAR and anaylis method,the final reasons of inappropriate behaviors and hazards would be pinpointed.This paper not only did theoretical research of risk assessment technology in the safety area,but also implemented the practical application based on CTCS-1 on-board equipment.The analysis results show that the proposed multi-resolution STAMP and corresponding analytical method can be used well in safty analysis of train control system.