Dsp-based Line Detection Of Frequency Shift Track Circuit Parameters

The railway transportation plays an important role in the development of the national economic. As the the development of the railway technology, the speed and the carry ability of the railway greatly improved. In order to assure the safety of the railway traveling, a higher requirement has been rased for the realtime security of the train. There are several technic skills to make everything run smoothly. The railway circuit is one of the most critical methods to insure safety transportation.The frequency-shift railway circuit is the main railway circuit in our country, including 18-information frequency-shift auto-blocking railway circuit made in China and UM-71 jointless railway circuit made in France which localized ZPW-2000. Both of them use the frequency as the transport parameter. Usually, the rail is used as the signal channel to establish the relationship between the signal equipment and the running train. As the serious environment where the railway circuit equipped, some testing is needed periodically to evaluate whether the railway circuit and the signal equipment are in a good state.The detecting systems based on the traditional methods are facing serious challenge. At the basis of the former research work and the analysis of the frequency-shift signal. As to the carrier frequency, the spectrum of the 18-information frequency-shift railway signal has two peaks, the carrier frequency is the average of the two peak frequency. The ZPW-2000 jointless track signal has only one peak, the carrier frequency is the peak frequency. This paper gives fast Fourier transform to check the signal and proves correctness with some tools.The TMS320F2812 is used as the core processing unit based the test mothed. The related circuits are well designed. Hardware platform is established and realized the display and the A/D sample.