交流电磁场钢轨表面裂纹高速检测信号处理模块开发OACSTPCD

Alternating current field measurement(ACFM)technology has a good application prospect in rail crack detection due to small influence from speed and lifting effect.However,the signal picking speed can cause the crack signal frequency to shift,resulting in quantization error,missed detection and false detection.In order to improve the reliability of ACFM technology in rail crack detection,signal processing module for high-speed detection of alternating current field rail surface crack is developed based on field pragrammable gate ar-ray(FPGA).The influence of detection speed on frequency shift of crack signal is studied by theoretical deriva-tion method,and the relationship between detection speed and effective frequency range of crack signal is built.A digital orthogonal lock-phase amplifier with cut-off frequency automatic tracking detection speed is de-veloped using FPGA.At the same time,a complete rail surface crack detection device and experimental system are developed.Finally,the detection ability and stability of the module are verified by experiments.