| Train control system which takes control of the interval and speed of train movement, and makes sure the safety and efficiency of the railway system, is a safety-critical system whose failures may endanger human life or the environment. System Requirements Specification (SRS) of the train control system is the basic documentation and standard for developing the system. Any defect of SRS may cause risks of system failure. The common way to find out the defects is modelling and verifying the SRS. However, the modelling methods in use-general modelling approaches, are not very effective. Because the modelling procedures are not specified in those methods, and the models may be inconsistent with the SRS. Moreover, the general modelling approaches can’t satisfy the needs of consistency and reusability of models, which may result in lots of redundant work.In order to solve the problems of model inconsistency, increase the reusability of models, realize the automation of model management, and improve the efficiency of modelling, a modelling language based on the domain-specific modelling method was presented in this thesis. The modelling language called Train Control System Domain-specific (TCSD in short) language, is a domain-specific language in the form of a model library. And the content of the thesis is as follows:1. Based on a thoroughly survey of the literature research, the domain-specific modelling methods were introduced, and then by comparing and analyzing the advantage and disadvantage of those methods, the best way of modelling the train control system was discussed.2. By analyzing the train control system, especially the system structure and principle, all the modelling elements needed in domain-specific modelling were defined. In this part, the properties, relationships and relevant rules of the modelling element were specified. Further more, a fault tree was used to analyze the failure of the train control system and to sort out the safety related properties of the modelling element.3. The abstract syntax was defined by translate the modelling element into the form of object, property, relationship, role, port and graph with the domain-specific meta-modelling language GOPPRR. And the concrete syntax was specified by designing the symbols of the modelling element.4. The rules were divided into four categories:rules constraining occurrences, rules constraining values, rules specifying dependencies between values of different properties or relationships of one element, rules specifying dependencies between different instances of elements. The ways to define the semantics are predefined rules and generator-based rules. In each way we specified all kinds of rules to get the formalized semantics. When the syntax and semantic of the TCSD language were defined, the domain-specific modelling language and a usable model library of train control system were constructed.5. In the end of the thesis, an application was provided to demonstrate the domain-specific modelling approach. The TCSD language was applied to construct the model of the RBC handover scenario. By comparing the model to the models built by general modelling language, the advantages of TCSD language in model consistency, reusability and model management were proved. |
