ZPW-2000轨道电路信号的解析方法

Analysis Method of ZPW-2000 Track Circuit Signals

介绍国内铁路信号系统ZPW-2000制式轨道电路的基本原理和信号特征、轨道电路信号传输路径和工作环境以及轨道电路信号解析的安全意义。阐述解析轨道电路信号的一种有效方法,通过时域过零检测的方法求取瞬时频率频偏,根据瞬时频率频偏与给定载频信息判断轨道电路载频信息,同时获取只有轨道电路上下频偏的低频信息,再通过频域Zoom-FFT求取低频信息。该方法既能满足低成本的CPU性能要求,又能在机车或牵引电流引起的信号幅度漂移的环境下稳定解码。

This article introduces the basic principles and signal characteristics of ZPW-2000 track circuits for national railway signal systems in China,the signal transmission paths and working environment of the track circuits,and the signifi cance to safety of analyzing track circuit signals.An eff ective method for analyzing such signals is introduced,which is used to calculate instantaneous frequency deviation through time-domain zero-crossing detection.Information on the carrier frequency of the track circuits is determined according to the instantaneous frequency deviation and the given information on the carrier frequency.At the same time,low frequency information is obtained regarding only the upper and lower limits of the frequency deviation of the track circuits,and then low frequency information is obtained through the frequency domain Zoom-FFT.This method can not only meet the requirements for low-cost CPU performance,but also perform decoding in a stable way in the case of signal amplitude changes caused by locomotive or traction currents.