摘要：城市轨道交通行车密度大、间隔短、速度快，轨道电路的移频信号对保障行车安全发挥了重要作用。随着我国列车速度的不断提高，铁路运输能力逐年增强，铁路在我国国民经济生活中的作用越来越重要。为确保铁路运输的安全畅通，如何精确快速的检测轨道电路移频信号成为一个重要课题。35690
目前，我国电气化区段的轨道电路有25Hz交流计数电码轨道电路和75Hz交流计数电码轨道电路以及移频轨道电路多种制式共存。本文以电气化区段轨道电路中较为常用的25Hz交流计数信号和ZPW-2000A无绝缘移频轨道电路信号为例，对这两种信号进行分析研究。由于现场环境下有各种干扰源的存在，本文首先对这两种信号进行时域和频域上的分析，并分析干扰信号的噪声来源，利用小波分析方法对25Hz交流计数信号和ZPW-2000A无绝缘移频轨道信号进行降噪处理和检测。从仿真结果可以看出，小波分析检测交流计数信号的误差小、抗干扰能力强，利用这种方法可以有效地克服传统方法0、1阈值很难选取的缺点，并能得到上下边频利用小波检测分析这两个信号的方法，这对提高铁路信号的检测准确性地具有重要的现实意义。
关键字： 轨道电路；移频信号；小波变换 ；降噪；信号检测
Track Circuit Frequency Shift Signal Detection and Processing
Abstract：Traffic density of city rail traffic, interval is short, fast, play an important role in frequency shift track circuit to ensure the safety. With the continuous improvement of train speed in our country, the railway transport capacity increase year by year, the railway in our country is becoming more and more important role in the lives of the national economy. In order to secure safety and smoothness of railway transport, how accurate, rapid detection of track circuit frequency shift signal has become an important subject.
At present, there are many formats of track circuit in the electrified section in China, such as 25Hz AC counting signal, 75Hz AC counting signal, frequency-shift keying track circuits. As the track circuit of 25Hz AC counting signal and ZPW-2000A non-insulated frequency-shift keying track circuit is used widely in electrified section, this paper take them as example. As there are various sources of interference in the field environment, this paper firstly analyze these two signals both in time domain and frequency domain, secondly use the theory of wavelets transformation theory to de-noise the noise-signal, finally analyze the signal of 25Hz AC counting signal and frequency-shift keying track circuits. From the simulation results can be seen that the wavelet analysis of signal detection AC counting error is small, strong anti-jamming capability, using the method to overcome the shortcomings of traditional methods 0,1 threshold is difficult to select, and get below the frequency of using wavelet the analysis has important practical significance and practical value of these two signal detection methods to improve the accuracy of the railway signal detection.
Key words: Track circuit, Wavelets transform, AC counting signal, De-noise, Signal detecting
目 录
1 绪论 1
1.1 铁路信号系统发展概况 1
1.2 轨道电路的介绍 1
1.3 轨道移频信号检测技术的现状 2
2 轨道电路移频信号的建模 3
2.1 轨道电路 3
2.1.1 轨道电路工作原理 3
2.1.2 轨道电路作用和技术要求 4
2.2 轨道移频信号 4
2.2.1 25Hz交流计数信号的时域分析 4 ZPW-2000A轨道电路移频信号的检测与去噪处理+程序:http://www.751com.cn/tongxin/lunwen_33744.html