Hardware Design Of Track Frequency-shift Parameter Detector

With rapid development of economic, China depends on railway transportincreasingly. Therefore, train’s operation speed and railway’s utilization ratioattain higher and higher level. With promotion of speed and efficiency, train’ssafety operation is paid much more attention than even before. Train controlsystem operation normally is very important which decide train operation safety.Jointless Frequency-shift automatic block system is a advanced train controlsystem in China. It transfers multiple control information by signal wire which iscomprised of track. Therefore，the track circuit of signal transmission, quality oftransmission signal and operation normally of jointless Frequency-shift automaticblock system affect safety of train operation. Making ensure of the safety of trainoperating, we need to eliminate hidden perils, test track Frequency-shift signalfrequency parameter of jointless Frequency-shift automatic block system andother electric parameters that can judge whether the device is normal.This paper particularly describes how to solve the practical problem ofparameter detection of Frequency-shift automatic block system and trackcircuit.It also analyzes the principle of track Frequency-shift signal which is akind of frequency modulation signal and use low frequency signal with controlinformation to modulate carrier frequency signal in order to generate sinusoidalAC signal.According to Frequency-shift signal spectrum characteristic analysis，amethod, which adopt frequency domain way to test Frequency-shift signal, couldtesting carrier frequency and low frequency of signal. This design can testfrequency information of track Frequency-shift signal. It also includescompensation capacitor detecting function and automatic range multimeterfunction in order to realize synthetical detecting purpose.On testing method andrealizing function foundation, this paper design central process and controlmodule which taking OMAP L137of DSP+ARM dual cores processor as core. It also includes Signal Conditioning Circuit design, self-test signal circuit design,protection circuit design, external interface design, charging circuit design, etc.Finally，this paper use multisim10to simulate hardware circuit. Meanwhile，italso use Cadence to simulate signal integrity of high speed signal wire. Of course,it provided corresponding analysis as well. Testing result show that the hardwarecircuit could realize corresponding function. It in step with design requirement inorder to testify that the method is correct.