A FPGA based ultrasonic rail flaw detection system

Ultrasonic testing is one of the main methods used for rail flaw detection. In order to detect the flaw in different positions in the rail and increase the detecting accuracy, multiple ultrasonic probes are needed. It is difficult for real time detecting when the rail testing vehicle runs at a high speed. In this paper, we present a FPGA (field-programmable gate array) based automatic rail testing system which has multiple transmitting and receiving channels. The real-time signal processing is carried out in the FPGA including filtering and envelop detection. The 2D B-scan image is processed in the host computer for the flaw detection. Currently, the processing system is able to work for a rail testing vehicle with the speed higher than 20 km/h.