针对目前列车轮对探伤效率低的缺点，设计了一种基于电磁超声的列车轮对踏面在线探伤系统。该系统结合表面波和电磁超声技术的优势，利用嵌入到钢轨轨头的六通道电磁超声探头，实现轮对踏面全面探伤；采用正交试验方法优化电磁超声换能器，提高了系统探伤性能；通过电磁超声大功率发射和低噪声接收电路完成超声波的发射和接收；采用基于现场可编程门陈列(FPGA)的控制及数据采集电路，实现装置的控制、数据采集、传输等功能；通过上位机对探伤数据进行处理、显示。试验表明，系统能够有效检测出轮对踏面伤损，具有无需耦合剂、检测效率高的优点。

In view of the low efficiency of wheel detecting device, an online wheel detection system based on electromagnetic acoustic technology has been investigated. This device combines the advantages of surface wave and electromagnetic acoustic technology, by setting six detecting devices in the rail track to inspect the whole wheel surface. By adopting orthogonal test method to optimize electromagnetic acoustic transducers, the systems detecting ability is improved. Surface wave is excited by high power transmitting circuits and received by low noise receiving circuits. Control of the device and acquisition and transmission signal are accomplished by FPGA. The software on computer is developed to process data and display results. Experiments show that the system could detect flaws on the wheel surface efficiently, which indicates the device has advantages of independent of couplant and high testing efficiency.