Modeling And Realizing Of On-Board Equipment Of CTCS-2 Train Operation Control System With UML

Along with the development of our country's economy, the safety and efficiency of the railway system are becoming higher. And the automatic train control system plays significant role in assuring operation safety and improving operation efficiency. Among which, the Automatic Train Protection is one of the main component, and it is used to supervise the speed of the high-speed train in real time and continuously, to control the brake system automatically and to realize automatic train protection. This kind of control system needs to be high safety, and the software must be designed safely. In this paper, the author has researched the modeling design of CTCS-2 ATP on-board device software.The paper introduces meeting problems in developing train control system. With the rapid development of computer technology, the safety assurance methods and techliologies formierly used could no longer satisfy the ever increasing safety demand of complex computer system. Recently, model based design method give a possible solution to safety assurance of Automatic Train Protection.The paper introduces the advantage of modeling with UML and real-time embedded-system modeling tool Rhapsody. To avoid disadvantage of waterfall life cycle used in development, this paper brings Rapid Object-Oriented Process for Embedded System (ROPES) in the modeling of CTCS-2 ATP on-board system.The software development of ATP is divided into four stages: analyzing, design, implementation and testing, according to this process. Taking modes and levels transitition as examples, this dissertation introduces the concrete application of ROPES in ATP software development in details. The model development method with UML brings abstract layer of software development from traditional code layer up to the model layer, so that the developer can be absorbed in the specific domain problems instead of cockamamie program codes. It can also test and verify the system function on the model layer. The codes generated automatically from UML model are based on the real-time framework technology and can execute on the target platform efficiently and can change with the UML model synchronously. So this method not only solves the existing disjointed problem between the traditional system model and system implementation but also reduces the iterative lifecycle and guarantees the software quality. Finally, by realization of the model on VxWorks, the author does white-box and black-box test on the model, which indicates the feasibility and validity of the model method in this paper. The method to design software of ATP on-board device takes advantage of UML. On the premise of guaranteeing the safety, reliability and real-time of the system, it simplified the management of system resource, reduced the complexity of software design and improved the transplant, hierarchy and integrality of the software.