Study on describing problems of temporal interval centered synchronization within DRIS

As a complex and time-critical system, railway interlocking system (RIS) is vital for the safe operation of a train in station. For the next generation RIS named Distributed Railway Interlocking System (DRIS), the synchronization issue between internal devices, which means the guarantee of a well-organized cooperation, plays an important role in ensuring trains´ safety running. Therefore, as a prerequisite a clear depiction of the synchronization within DRIS is essential. To that end, a temporal interval centered describing method is proposed. Firstly, considering the time shortage in UML statechart, the temporal interval is introduced to achieve the temporal extension of UML statechart. Secondly, the temporal statechart model of the DRIS is constructed with the method above. Finally, a brief analysis of the execution of internals of DRIS is given based on the constructed model, and the timeline mechanism is adopted to graphically describe the synchronization of internals of the DRIS by the relations between temporal intervals of states depicted in timeline diagram.