Data Safety Research Of Database Storage Unit In CBTC System

Communication Based Train Control(CBTC) system is the trend of urban rail transit in the future, which is used for transmitting information of train control and train state though bidirectional digital communication of wayside-train continuously. As a core component of the CBTC system, Database Storage Unit(DSU) provide the necessary data information for CBTC system, such as lane static data, dynamic data, the configuration data, management data, and Movement Authority data. The safety of data is the important guarantee of DSU and safety operation continuously of CBTC system. It is lead to serious accidents if there is any error of the data safety. Therefore, it is great significance to research the data safety of DSU for the whole CBTC system.Firstly, Based on currently research on database and database safety, this paper combined safety integrity level and CBTC system requirements, in accordance with the method of data safety and logic safety, researched on accuracy and real-time requirement, route description, structure were designed particularly. On this basis, data security was divided into data static safety and data dynamic safety to protect data safety.Secondly, on the basis of analysis of data safety, rules of safety record was constituted in order to ensure that the data into the database can accurately reflect the actual situation in line, checking of relevance relationship and protective measures of legitimacy wrong were designed to ensure that the inputting data was consistent with the line situation; MD5 algorithm was introduced to check data storage, in order to ensure that the data into the data storage unit were consistent with the data modified at the last time.Finally, the paper designs the security mechanisms of data transfer from the view of the dynamic data safety for the existing problem in the data transfer. It designs a method of consistency monitoring and check of distributed data based on the way of version control. Developed a strategy of maintain the consistency of data updating which is based on the version control, then built system simulation environment to verify the result. At last, the desired result was in consistence with design.