The Research On The Key Techlonogy Of Ultrasonic Phased Array Inspection Instrument

Ultrasonic phased array detection is an emerging technology of ultrasonicdetection technology in recent years. It can control the extent and location of theultrasonic beam scanning focus on by arranging the ultrasonic transducers accordingto a certain rule. Phased array ultrasonic NDT technique is becoming one of themainstream industrial NDT techniques because of its fast, flexible and efficientscanning beam focus control method, large dynamic range of the beam scanning andits real-time clear imaging. It has played an irreplaceable role in weld inspection of oilpipelines and large tanks in long-distance transportation. However, a lot of works stillneed to be done in the application of ultrasonic phased array inspection technology inchina. The design in this paper is a multi-channel ultrasonic phased array system thatcan automatically detect weld defects of large oil storage tanks. The main contents ofthis paper are as follows:1. The method in this paper gives a comprehensive description of the principle ofultrasonic phased array inspection. The focus law of ultrasound phased array scanningwas discussed as the theoretical foundation of this paper.2. A design of a32-channel ultrasonic phased array automatic detection systemhardware solutions is shown in this paper, including the ultrasonic pulses transmittingcircuit, the echo signals receiving circuit, the receiving channel selection module,etal. The design also gives the hardware system proposal associated with high-speedreal-time data communication system, including the configuration of double FPGAs,the overall power management and clock management, DDR memory circuitdesign,et al.3. The real-time storage and retrieval of data with high-speed and large-capacityis a technical problem in ultrasonic phased array nondestructive detection. To solvethis problem, FPGA was used in this paper as the main controller and two DDRSDRAM was used to achieve ping-pong storage by sharing the same PLL and DLL ina FPGA. Results obtained from system simulation and test showed that the designedsystem can be operated stably to store and transit16-bit parallel digital echo signalsampled by a125MSPS AD sampler without dead time. The real-time wave imageshowed in host computer proves that the data sent from FPGA is continuous. 4. The design gives a scheme of ultrasonic echo signal filtering by using DSPBuilder. The real-time wave image displayed in host computer shows the satisfactoryresults of filtering.The design in this paper has been applied in large oil storage tank weld inspectionrecently. It is currently in the testing stage. The stability and efficiency of this systemmeets the industrial ultrasonic nondestructive testing standards well.