Design And Implementation Of Track Frequency Shift Acquisition Based On Cortex-M4

In recente years, with the continous improvement of the Chinese railway operating speed, especially the strong popularities of high-speed railway Passengers and dedicated lines, how to ensure traffic safety has become a top priority issue of rail transport.Combining the widespread use of the railway ZPW-2000 A Frequency Shift Automatic Block System without insulation, this paper implements collecting accurately for frequency Shift signal by a single collector, using a detection algorithm for track frequency shift signal and dedicated hardware circuit. Oversampling achieves to obtain railway FSK signal frequency signal completely,.Digital filter technology basedon track Frequency Shift feature to extract useful signals effectively and remove interference; Primary and secondary frequency separation, separates scene mixed signal, and provides the basis for the subsequent parameter calculation;In connection with he requirements of detection accuracy for railway traffic safety,and the unimodal characteristic of ZPW-2000 A track signal spectrum, using a spectrum refinement and Fourier transform algorithm is to detect signal carrier frequency,is to meet the accuracy requirements of detection system;Using appropriate carrier frequency energy focus correction algorithm is to achieve accurate detection of low-frequncy modulation frequency for tracks frequency shift signal.Track Frequency Shift collector chosed the STM32F405 chip that based on Cortex-M4 core as the hardware platform,combined with embedded C and assembly language,achieved a frequency shift signal detection, Extensive testing results show that the product can detect the frequency shift signal in real-time and accurately and meet the site requirements.