Study Of Ultrasonic Pulse Detection System Based On FPGA

With the gradual maturity of ultrasonic testing theory and the extensive accumulation of practice and the rapid development of electronic technology and computer technology, ultrasonic testing system is developing towards the direction of digitization, automation and intelligence.Considering the current high price and low openness of related products at home and abroad, which bring many limitations and inconvenience to the researchers. Therefore, this project independently disigns a perfectly functional ultrasonic pulse detection system based on depth investigation of the domestic and foreign market.The new-designed detection system has the following functions: a high efficient and high performance high voltage DC/DC converter, the outout voltage can be adjusted continuously; The high performance of the pulse transmission module, pulse width, pulse frequency, pulse number and pulse repetition frequency can be adjusted to adapt to different piezoelectric sensors and different detection tasks; With two kinds of trigger mode: internal trigger and external trigger, and the output of synchronous trigger pulse, which can coordinate external module conveniently; Work mode supports the T/R and T/T, which can adapt to different detection scenarios flexibly; With high voltage protection module, which can realize high voltage and low voltage’s isolation; The fixed gain control and the time gain control methods can be approved;Multilevel lowpass fliter and highpass fliter can be approved; Sampling frequency can reach 100MHz; Data can be uploaded real-time through Gigabit Ethernet port.About the software part, using the hareware description language HDL Verilog design the logic control program of FPGA according to the idea of modular design. Demo VC++ program, which is based on the communication of the network, has been designed to meet the users’ further development.Performance test results show that the system has achieved the target function and the performance is good. And it has been widely used in ultrasonic nondestructive testing field, including ultrasonic testing component of residual stress, surface type component defect guided wave array detection, single robot hand complex curved surface defect detection, etc.