| 摘要 |
<p>One of the fundamental problems of Coded Current Automatic Block (Bacc) system currently in use in about 5000 miles of the RFI (Rete Ferroviaria Italiana) network is the need to use insulated joints to separate various sections of track that are one of the most frequent causes of track breakage. The basic idea of this invention is the separation of the different sections of the line not through galvanic isolation of the rails but through short circuits between the rails. This allows greater consistency along the rails, eliminating completely the delicate isolated joints. Short circuits isolate an electrical circuit that "shifts" in accordance with the movement of the train so that in front of the train there is always a generator present which is able to generate the coded current that is read on-board in accordance with specific railway protocol. The presence of rolling stock can be detected by special current sensors placed in specific places along the rail. The sensors detect the train arrival by means of the short circuits generated by the axles of the train eliminating, at the sensors, the current impressed by generators. Signal transmission to the train remains unchanged compared to previous systems so that no changes in on-board subsystems are required. The achievement of the required safety integrity level is easily obtained because the system has the possibility to re-read what is transmitted to the train It is possible to install the proposed system in specific tracks of the line. The coexistence of tracks traditionally equipped (with isolated joints) and tracks equipped with the new system in the same line allow a gradual transition between the two systems. The system also allows the observation of electrical parameters of the rails, raising alarms in the case of specific types of breakage or damage of the rail.</p> |
