Research And Realization On Detecting Method Of The FSK Track Circuit Frequency Shift Signal's Parameter

Railway is the important basic equipment of the transportation in china, which is displaying extremely vital role regarding social economy's development. Therefore, it has an important significance to improve railway transportation efficiency and guarantee the traffic safety of the railway. The reliability of track circuit immediately influence railway's traffic safety, which is the basic equipment in controlling train's running, so it is indispensable to check the working condition of track circuit periodically.Frequency-shift track circuit is the main form of the track circuit in china. At present, frequency-shift track circuit in china include two standards:Chinese eighteen informations FSK Auto-blocking system and French introduced ZPW-2000 non-insulated track circuit system, both of which use frequency parameter to transfer the messages of train running. Because there are some drawbacks in traditional detection methods, and it doesn't adapt to the rapid development of the railway undertakings, it is high time to study a new detection method of the orbital frequency shift signals. In order to solve the problems, the research works of this paper as follow:Based on the relevant studies of the orbital frequency shift signals' detection method, this paper put up with a new method after studying the feature of the frequency shift signal's spectrum, which use spectrum correction and reduction based on the FFT algorithm through making the spectrum under leakage state revert non-leakage state by line position interpolation and synthesis of spectral range in low resolution spectrum, thus making shift frequency parameter received exactly and rapidly. Compared to the traditional spectrum detailing algorithm, this method has an advantage of give attention to both detection accuracy and real-time property. Additionally, during the realization of algorithm, this paper use low-sampling frequency technology in order to select a sampling frequency which can meet all the demands. Finally, based on the research of the algorithm, this paper designs the hardware system and circuit based on the TMS320F2812 DSP microprocessor.The new detection method proposed in this paper is tested by a number of simulation experiments with Matlab and is implemented with C. The results indicate that the new detection method is effective and feasible. The research works of the paper provide evidence for the design of frequency shift signal detector.