基于直接数字频率合成技术的轨道电路发码装置研究与实现

Research and Realization of Track Circuit Code Sending Device Based on Direct Digital Frequency Synthesis Technology

为了满足新颁布标准《轨道电路读取器(TCR)》(TB/T 3533—2018)对TCR的测试要求,提高受测设备检测效率,设计了一种基于DDS技术的轨道电路发码装置。硬件设计采用DDS功能芯片AD9958和数字信号处理器TMS320F28235,其中外部放大调理和滤波电路参考了芯片厂家的推荐电路,并对硬件设计参数进行了优化计算和调整。该发码装置发送的轨道电路信号具有相位控制精度高、频率转换速度快、噪声小的优点,且可以方便调节输出的电压和电流值。

To comply with the testing specifications of the recently published"Track circuit reader(TCR)"(TB/T 3533—2018)and to improve the detection efficiency of track circuit reader under test,a track circuit code sending device is designed by using direct digital synthesis technology.The hardware design of the code sending device adopts AD9958 as DDS chip and TMS320F28235 as digital signal processor.In addition,its external amplification conditioning and filter circuit refers to the circuit recommended by chip manufacturers and hardware design parameters have been optimized and adjusted.The signal output by the code sending device is characterized of high precision phase control,rapid frequency change rate and low noise,and its output voltage and current can also be regulated conveniently.