Research Based On TOFD Transceiver Subsystem

NDT technology (Non-Destructive Testing) is a method that acquire the physical and chemical information of the analyte's quality withut destroying the original physical and chemical state of test substance.Ultrasonic testing is widely use and faster develop relative to other NDT technology. Time of flight diffraction method (TOFD) is different from the conventional method. The latter use the ultrasound that reflect in the surface defect to test defects, while the former use the ultrasonic tip diffraction theory to test defects.The drawback of the conventional TOFD is that the location of defects is in elliptical arc (elliptical focal point is the probe). Traditional TOFD must use the B scan (along the probe to be detected at the lateral movement) to locate the defect accurately. Compared to traditional TOFD, TOFD-LWE (double elliptical location method) has one more receiving probe, the defect location is at two elliptical intersection, so it can locate the defect accurately without B scan.The thesis research the TOFD-LWE subsystem. First of all, complete the data processing systems and the software programs according to the system 's requirements. Then, complete the design and debugging of hardware platforms according to the system's scheme. The hardware platforms include the signal conditioning, data acquisition and the power amplifier. The data acquisition rates up to 125MHz. The gain of the signal conditioning can be controlled through the FPGA flexibility. Finally, introduce the software design and debugging of the FPGA, it include the RS-232 serial transmit and receive modules, Mcasp transmit module, pulse transmit module and time gain module.