铁路移频论文——硬件.doc

铁路移频信号检测仪的设计 ——硬件设计 摘要 信号检测是保证列车安全运行的重要因素之一，铁路段和机车联系的方式之一是通过铁轨作为介质由发码器发送移频信息。为保证信息的正常发送维修人员须定期对移频信息进行检测。 当前，铁路提速的发展，多信息移频自动闭塞系统已经应用于铁路区间行车自动指挥系统中。我国铁路机车信号主要采用相位连续的频移键控FSK（Frequency-shift keying）调制方式。FSK是利用数字信号对载波频率进行键控调制的一种方式。移频信号是一种频率调制信号，通常选择550至850HZ频率为中心频率，70至30HZ为信号频率，不同的信号频率值代表了一定速度控制信息，直接指挥列车的运行速度。移频信号的定时检测并发现干扰源或故障，这样对确保铁路行车安全有重要意义。 本课题研究内容：测量电化区段和非电化区段的移频信号电压值、电流值、调频信号的上边频、下边频、单频、低频 、中心频率、中心周期的至少八种信息的参数测量。 在信号的采集上选用多路开关芯片并设置合适的量程范围.。采用有源滤波电路对信号进行适当的处理，将交流信号通过AD736转化为直流信号并经过AD7705将模拟信号转化为数字信号，并用LM2907以及MAX7400对其解调，最后选用AT89C4051单片机以及LCD显示以达到准确测量各种参数的目的。 关键词 ：移频信号；测宽法；参数测量 The design of railway Frequency-shift detector — design of hardware Abstract Signal detection is one of the important factors to ensure the safe operation of trains . The contact of the Railway and locomotive with each other is by the tracks as a media and sending the shift frequency information by the coder. In order to ensure the success of sending information,the maintenance staff have to detect it regularly. Currently, with the improvement of the speed of trains ,the multi-frenquecy shift automatic blocking system has been used in traffic automatic command system 。In our country ,the railway locomotive signal mainly uses the modulation of the continuous phase frequency shift keying。FSK is the way using the digital signal to modulate the frequency shift keying signal , usually choosing 55oHZ to 850HZ as the center frequency, 70HZ to 30HZ as the signal frequency ,the different signal frequency represents a certain speed with controlling information ,directly commanding the speed of train .It has a great significance that detecting frequency-shift signal in timing ,finding the sources of interference and fault to ensure the safety of railway System. The content of this theme is as follows: measuring the parameters of frequency-shift signal in the electrical and no electrical block. These parameters include voltage and current of FSK signal, upper frequency, lowe