移频轨道电路参数测试仪的研制

Research of Frequency-shift Track Circuit Parameter Measurement Instrument

针对开、短路法测试轨道电路参数将影响正常行车秩序的问题,依据锁相环数字解调原理和选频技术,设计了由单片机AT89C52对整个系统进行控制的在线测试轨道电路参数测试仪.采用锁相环CD4046,从移频信号中解调出低频调制信息,应用选频技术,实现移频信号与工频及其谐波干扰信号的分离.实验及现场测试表明,本测试仪具有成本低、准确度高、性能稳定可靠的特点.

Considering the problem resulted from measuring track circuit parameter using the method of open or short need time, which affect the normal order of trains running, according to phase -locked loop digital demodulation principle and frequency selection technique, a measuring instrument controlled by the single chip microcomputer AT89C52 to on-line measure track circuit parameter was designed. Phase -locked loop CD4046 was used to demodulate low frequency modulation message; and the frequency selection technique was applied to realize the separation of frequency-shift and industrial frequency signal as well as their harmonic wave disturbance signal. Test and application prove that the measurement instrument has low cost, high precision, and stable and reliable performance.