Investigation Of Distributed All Electronic Computer Interlocking System

Computer interlocking system is to achieve station interlocked by using computer as its main technique. Its main function is to command driving, ensure safety, and improve the efficiency of railway transportation and working conditions. The centralized control mode with the interlocking computers as its. core is the current mainstream of computer interlocking systems, however, this type of control mode always shows many problems such as centralized risks, higher project costs, and difficult tasks of system maintenance.Based on the study of the structure and function of the existing computer interlocking system, and by comparison of different formats between the domestic and international computer interlocking structures, under the main circumstances that the railway is overloaded and high-speed, the thesis reveals some limitations exposed by the current mainstream of domestic computer interlocking system. By introducing the concept of field control, other techniques such as the distributed control, intelligent control and optical fiber communication technology are incorporated, and a kind of distributed general electronic computer interlocking structure is proposed.Ethernet passive optical network (EPON) is a type of optical fiber access network technology which integrates common advantages of PON technology and Ethernet technology, such as low cost, high bandwidth, simple maintenance, strong expansibility, easy to upgrade, flexible and fast, and so on. And EPON is very hot and popular in the field of optical access network. So, the new distributed interlocking structure using EPON networking technology puts forward the optimization scheme of optical fiber redundant ring network structure, then on the basis of CAN data frame format, a variety of methods such as message number and error-controlling codes and positive and inverse code are used to set messages to the side of safety. In addition, by introducing the concept of time delay label into the reserved bits of CAN data frame, the value of the label is determined through the synchronous clock time of the communication system.By using field controller to realize the distributed control of on-site signal equipments is the key of this interlocking structure, therefore, in this thesis, the structure and function of the field controller are designed in detail, and in case of its switch control module, the switch control is simulated and implemented.By analyzing the relationship between reliability and safety of the signal equipment, it is pointed out that the reliability standard related to the railway signal equipment is not perfect at present, and according to the path control function, the reliability block diagram of distributed all electronic computer interlocking system is set up, the quantitative analysis and simulation are also done for the reliability diagram. The results show that the system operation is stable and reliable, and the results can be used to provide evidence for the regular maintenance of all electronic computer interlocking system.