Research And Realization Of Simulating On-board DMI In CTCS Based On Reusable Framework Theory

Following the fault-safety principle,On-board subsystem of CTCS (Chinese Train Control System) is designed as a safety-critical system,which is a crucial part that can guarantee the efficiency and safety of the train movement.As train drivers do not understand the internal principles and functions of on-board devices, while on-board DMI(Driver-Machine Interface) is the only way to achieve the interaction between them,DMI must shield the complex internal structure of on-board subsystem and use friendly way to guide the driver to complete operation,in order to ensure their close cooperation and give full play to the on-board subsystem.Therefore, the research of DMI has a very important significance.Based on CTCS-2,the CTCS-3 simulation and testing platform has been initially formed.The simulation system could launch research in a more flexible way,with advantages of low cost and short cycle.For DMI,the problem to be solved is:how to effectively learn from the successful experience of CTCS-2,quickly and efficiently realize high-quality DMI to meet the needs of CTCS-3,which can be used as reusable resource for further research.Based on Software Reuse theory,a reusable framework based solution is presented.First,Software Reuse theory and Catalysis method is briefly introduced,and the functions of DMI are illustrated.The DMI service model is built up by using Catalysis method,and from train driver's point of view,the functions is divided into two parts: supervision and control.Also,the sequence of interaction between train driver and DMI is presented.After that,based on typical operating scenario,the model refinement is carried on and requirement of DMI is deeply analyzed.Second,On the basis of model refinement,by using decoupling technology of Catalysis,a fundamental framework of the DMI is established,which has a bidirectional structure with four layers:data flow between DMI and Vital-Computer has two directions,four layers include communication protocol layer,data transforming layer, data processing layer and user interface layer.In accordance with the order of these layers,taking reusability as the goal,a set of frame templates of simulating DMI is established and functions,such as communication,data analysis,interface layout,graph drawing,audio playing,functional buttons,are designed to be general and reusable.Finally,with the advantages of these frame templates,simulating DMI has been realized by using C++Builder 6.0,and flow charts,as well as algorithm,are explained. Then taking some specific problems in the process of development for example,the validation of the frame template's reusability is carried on.The result indicated that,for simulating DMI,the method based on reusable framework is able to avoid repeated effort,and to achieve a convenient means of development with existed resource.