Design And Implementation Of Real-time Object Database In Subway Monitoring And Control System

With the development of subway monitoring system integration and diversification of specialized interconnection, the information model becomes more and more complex. The real-time database based on relational model appears to be unable to describe a complex object of monitoring system; and what is worse, it is lack of flexibility in adapting to the ever evolving objective system.Using object-oriented modeling techniques the equipments and their functions of the monitoring system were analyzed and molded; the monitored equipments were mapped into the database classes and objects;complex objects were described through simple object compositions; various kinds of data type inheritance and composition relationships were defined; and data and library models that utilized in the monitoring system were established. Based on the technical performance requirements of real-time monitoring database for the subway monitoring automation system, a real-time object database MACS-RTODB which applied in subway integrated monitoring system was successfully designed and implemented proceed through the memory-based storage strategy in combination with event-driven architecture software design thoughts. It not only maintained the basic characteristics of object-oriented databases, but also took the real-time requirements into account, which satisfied the needs of the subway monitoring system. In addition, this paper further researched the openness for the real-time object databases. Tcl scripts embedment and its application were successfully carried out.The real-time object database established through above mentioned methods is a useful exploration for the application of the object-oriented, event-driven and scripting technologies in the subway monitoring and control automation system.