Design Of Central Control Unit In Metro Surveillance System And Study Of Train Control Network

With the increasing transportation load, the metro system keeps accelerating, and the idle time is declining. Therefor, the security and reliability of the train become more and more important. Train Surveillance System is designed to realize automatic drive, speed limit, malfunction analysis and remote control. These functions reduce the risks from manual operation, and enhance the response performance and reliability.The detailed design of the central control unit used in the train surveillance system was described in this paper, which belonged to the project "Localization of Guangzhou Metro Line No.1". The new train bus and vehicle bus were chosen in this design based on the analysis of static service performance of the original module bus, and detailed research was made on the protocol policy of the bus.Central control unit consisted of 4 modules: host PC, module bus adapter, vehicle bus adapter and train bus adapter. The host PC was designed with uC/OS-II portinged on the PC104 SBC. The SBC connected with a HDLC adapter and two LON adapters through PC104 bus and combined to be a complete central control unit. HDLC adapter was designed based on ARM7, and adapted between HDLC and PC104 buses using a dual port RAM with partitions. As for the LON adapter, an existing product with high-level parameters was installed on the SBC, and the interface for data access with SBC was described in the paper.Through several networking tests, the central control unit was verificated to be reliable under heavy load environment and localized successfully.