Research Of Urban Rail Main Line Interlocking System Based On SCADE

Communication-based Train Control(CBTC)system has become the preferred solution for urban rail traffic signal system.As one of the key parts,Computer Based Interlocking(CBI)system is a typical safety demanding system,responsible for ensuring the logical operation of traffic safety.In order to meet the requirements of high density and high safety of modern urban rail transit,interlocking system has added new functional requirements,and its logic operation is more complex.Therefore,how to ensure the safety and correctness of the development for urban rail interlocking system is particularly important.In this paper,the interlocking system of urban rail transit is described in graphical modeling by using the high-security application development environment SCADE,in order to reduce the fuzziness of traditional text description and meet the requirements of development of high security the system.The interlocking data is analyzed according to the characteristics of CBTC mode and back-up mode.Taking specific interlocking area of station map as an example,the data structure is defined based on the characteristics of the signal equipment and the interaction information between the interlocking and other systems.The route control is divided into route setting and release module.The route setting module includes the route request,route check,direction locking,protection zone lockingand signal control.The release module is divided into the normal release,reentry release,protection zone release,cancel release and fault release.The above modules are modeled by the combination of data flow diagram and state machine.The automatic pass and automatic trigger route is designed separately.Finally,the test case is written,and the route control process is simulated by using SCADE.The safety attribute of the signal lighting-off in CBTC mode is designed,the safety attribute and the observer combination model is established,the function of the system is verified and the verification result is analyzed,which shows that the designed model satisfies the functional requirements and safety requirements.