Rail flaw detection system based on electromagnetic acoustic technique

As a result of the development of higher speeds and heavier loads of rail networks, rail defects have been more serious than ever before. Current piezoelectric ultrasonic detection devices are often inadequate for rail inspection, due to high misjudgement or undetected error rate, and complex structure. This paper introduces a novel rail detection system. The system is based on multi-channel electromagnetic acoustic transducers under the control of DSP. Cumulative average and cross-correlation algorithms are realized by FPGA, exploiting the advantages of FPGA in high calculating speed and designing flexibility. Combining EMATs with FPGA, the system is free of couplant, compact in structure and low use-cost, and can realize an overall detection of rails.