18. Safety Confirmation-Based Train Control System

To sustain regional railways in the future, further labor savings in maintenance and train operation activities are necessary. Reducing communication infrastructure through the use of public communication networks and the introduction of automatic train operation for regional railways are promising approaches. However, if different systems are introduced for each railway line according to its specific conditions, system design and maintenance costs will increase.

To address this issue, we developed the Safety Confirmation-Based Train Control System that enables safe train operation using common control logic regardless of railway line scale or type of communication network employed. Unlike conventional systems, which stop trains in the event of communication interruption or delays, the proposed system maintains the route setting that is confirmed safe using bidirectional communication between ground and on-board equipment prior to the communication disruption, and preserves the locked status of wayside equipment. Even if communication interruption occurs, train operation safety can be maintained as the system maintains the same state that existed before the disruption (Fig. 1). This enables the use of public communication networks, where communication interruptions and delays must be taken into account.

Verification tests of the prototype system on a commercial line confirmed that a test train could be operated safely and stably using public communication networks. Furthermore, by defining the minimum information required for communication between on-board and ground equipment, interoperability was achieved, and tests on a commercial line verified the feasibility of a multi-vendor system (Fig. 2, Table 1).

Based on the results of the verification tests, we proposed a common specification for this system. By introducing equipment based on this specification, maintenance labor can be reduced by reducing communication infrastructure. It can also serve as the train control system foundation for the introduction of automatic train operation on regional railways.