便携式AF904数字轨道电路测试仪设计与实现

设计一套便携式AF904数字轨道电路测试仪，以解决日常维护保养中传统轨道电路维护手段维护效率低，可测试参数少，无法实现数字轨道电路解码和连续测试等问题。在研究了AF904轨道电路工作原理、技术参数、现场应用情况的基础上，基于数字信号处理（DSP）的离散短时傅立叶变换（DSTFT）、数字滤波等关键技术，实现了对AF904轨道电路基本参数（电流、电压、频率）的测量、显示、数据的解码分析及参数异常报警等功能，并开发了基于安卓系统的智能终端APP，实现了在手机、平板电脑等智能终端上实时查看测试数据的功能。结合专门研制的轨道拖行小车还可以实现在钢轨上连续测试。地铁线路现场测试结果表明，该测试仪解码准确，对轨道电路基本参数的测试精度在±5%范围内，满足日常维护的要求。该测试仪的研发，解决了传统测试手段效率低、只能测试有限的参数的问题，提高了AF904轨道电路的维护保养的效率，为故障诊断提供了数据支撑。

Portable AF904 digital track circuit tester

A portable AF904 digital track circuit tester was designed to solve the problems of low maintenance efficiency, few test parameters, and unable to decode and test the digital track circuit continuously. On the basis of studying the working principle, technical parameters and field application of AF904 track circuit, the measurement,display, data decoding and analysis of basic parameters (current, voltage and frequency) of AF904 track circuit were implemented based on the key technologies of digital signal processing(DSP), such as short-time Fourier transform(DSTFT) and digital filtering. The intelligent terminal APP based on Android system was developed, which implemented the function of real-time viewing test data on mobile phones, tablets and other intelligent terminals.Combined with specially developed track trailer, it could also be tested continuously on rails. The field test results of metro lines show that the decoding accuracy of the tester is accurate, and the test accuracy of the basic parameters of track circuit can reach + 5%, which meets the daily maintenance requirements. The development of the tester solves the problem that the traditional test method is inefficient and can only test the limited parameters. It improves the maintenance efficiency of AF904 track circuit and provides data support for fault diagnosis.