Design Of Multi-channel Ultrasonic Testing System Based On PCI Bus

Ultrasonic testing (UT) is one of the most widely used detectiontechnology in the industrial production.The ultrasonic testing began in the20thcentury,for traditional ultrasonic testing technology,the workpiece is detected bymanual A-scan,it is time-consuming and its result is affected by artificial factor,so it can not meet the needs of modern industrial production. the design ofmulti-channel ultrasonic testing system based on PCI bus is described throughthe study on thin-walled cylinder ultrasonic testing method.The system isrelying on the computer, uses the PCI bus for data transfers and the hostcomputer for data processing. It is a good application for information processingtechnology in combination with conventional ultrasonic detection technology.In the paper, starting from the principle of ultrasonic testing of thin-walledcylinder, ultrasonic flaw feature extraction method and data collection andtransmission mode are put forward. The simple display software for a graphical interface and system control software are finished. In the system, pulse-echoultrasonic testing method is used in ultrasonic testing, multi-channel andmulti-probe are introduced to detect flaw of different trend, and multipleworkpieces can be inspected at the same time. The system consists of three parts:Front-end processing circuit is responsible for ultrasound probe trigger andultrasonic echo signal processing such as amplification, filtering, detection andpeak hold. PCI data acquisition and control card provides control signals for thefront-end circuit. AD7938on the card is used for sampling the echo signalprocessed by the front-end circuit and for communication with the hostcomputer by PCI bus. The collection and transmission at the same time arerealized by Ping-pong data transmission with dual FIFO. The main software forhost computer system is written in VC++6.0and the drive program for PCI busis generated by the WinDriver tool, which have finished the ultrasound dataprocessing, judgment, display, storage and system parameter settings and otherfunctions. At last, the system is tested with artificial defects of standard workpiece.The test results show that the detects can be detected preferably and the desiredperformance index is achieved.