With rapid development of communication technology, particularly radio technology, a train running control system based on communication technology is researched increasingly deeply, and a Communication Based Train Control System (CBTC system) emerges accordingly. The CBTC system is a control system for realizing safety protection of the train based on the bidirectional train-to-ground wireless communication technology and the moving block control principle. The CBTC system is used for replacing the track circuit as a medium to realize running control of the train. The CBTC system is increasingly widely applied to train running safety protection of urban rail transit.
Only if the CBTC system recognizes the marshalling length of a train entering into a CBTC control area and determines that no vehicle (e.g., a track engineering maintenance vehicle) exists in a safety range in front of/in the rear of the train, the CBTC system provides movement authorization for the train. That is, the CBTC system transmits a safe running direction, a safe running distance and other information calculated accurately to the train. In the existing CBTC system, a transfer track is generally provided at the boundary (such as a connecting line between a departure line and other lines) of the CBTC control area, and a trackside CBTC device is provided beside the transfer track. The trackside CBTC device receives information reported by an on-board CBTC device of the train entering into the CBTC control area, and parses the received information to obtain the marshalling length of the train. The trackside CBTC device transmits movement authorization to the on-board CBTC device only in a case of determining the marshalling length of the train and determining that no vehicle exists in the safety range in front of/in the rear of the train.
Since different trains usually have multiple different marshalling lengths such as six compartments or eight compartments, hybrid running of trains with different marshalling lengths is to be realized in a running line of the train. The existing CBTC system has to quickly determine whether a vehicle exists in a safety range in front of/in the rear of the train, in order to timely provide the movement authorization for the train. Therefore, only one type of train with the fixed marshalling length can run in the same running line generally, which limits the hybrid running of trains with different marshalling lengths.