Study On Distributed Railway Signal Generator

With the rapid progress of railway in China, especially the railway strategy of accelerating speed, the railway signal equipments are also making a developing progress. As the important role in train onboard system, whether the cab signal equipments work well directly affects the locomotive's performance security and efficiency. So it is important and necessary to detect the railway cab signal when the locomotive pulls in or out the line.The paper's main work is to design a railway signal generator scheme DCS theory based to satisfy the requirement of detecting cab signal in our country, in this system, the advanced DDS technique is used, the generator's hardware and software is designed and realized.The information characteristics of track circuit signal in automatic block system of our country are analyzed in the paper, and combined with the demand of detecting cab signal in railway field, the railway signal generator's function and technique parameter are studied and given in the paper.The railway signal's "fail-safety" principle is used in the system design considering the essentiality of detecting railway signal, by adding a closed-loop feedback circuit to detect the signal that the generator sends, the system can ensure the reliability of the signal, which realizes the automatic detecting of the system failure.The characteristics of the railway frequency shift signal are analyzed in the paper, DDS theory based the method of generating FSK signal using DDS is given. The whole hardware of the railway signal generator is designed and realized, in the paper the hardware frame and the work principle of the in-out module, the signal sending module, the control and detection module is analyzed.The system's flow chart of main program, input subprogram, interrupt subprogram and detection subprogram is given in the paper. The system's control flow and detection flow is analyzed particularly.In the end, the generator's detection in theory and experiment is made. We can see from the result that the generator meets the demand of the parameter made in the design.In conclusion, the distributed railway signal generator is multi-function, multi-channel, high precision; it has easy extended capability, man-machine interaction, and it can satisfy the "fail-safety" principle. The generator designed can meet the demand of detecting cab signal while the locomotive pulls in or out the line.