The Design For Data Collection System Of Tofd Ultrasonicweld Flaw Detecting Based On Fpga

TOFD (Time of flight diffraction) is one of the most advanced technologies in the industry field of ultrasonic nondestructive detecting. Sizes and locations of flaws could be gotten according to the difference between the time-intervals of return diffraction signals from the tips of flaw. It has been widely used in weld flaw detecting currently at home and abroad. There are many remarkable advantages such as highly detecting speed, precision, detectable rate, accurately locating flaws and convenience, etc.It designed a data collection system based on the TOFD ultrasonic weld flaw detecting. It collects analog data and transforms them to digital, using Slave FIFO transportation model in USB and FPGA to transport them to PC. Meanwhile, another experiment platform is set up with Focus-LT equipment which is made by Olympus Company, getting data and images to compare with this design.Firstly, the overall implementation scheme of the data collection system is presented, including hardware circuit plan, way of transportation and processing data, and the type of FPGA chip, USB controller, probe, encoder, etc.Secondly, USB theory is summarized firmware program in USB Slvae FIFO model based on CY7C68013is composed. Parameters like pipes, interfaces and interrupts are set.Thirdly, A/D data sampling circuit and modules based on FPGA which used VHDL language is designed, including clock module, controlling module, FIFO and Slave sequence controlling module.At last, after the debug of hardware&software is completed, components and chips are chose, transmitting speed is above40M/S. Meanwhile, another detecting experiment platform is set up with Focus-LT, data from two suits of experiment platform are compared. As expected, results demonstrate the correctness and applicability.