Research On Ultrasonic-testing Virtual Instrument

In order to improve the efficiency and reliability of the ultrasonic-testing, a type of ultrasonic-testing virtual instrument of high ratio of performance to cost is developed successfully. The traditional ultrasonic-testing instrument technology, virtual instrument technology, technologies of computer, electronics, digital signal processing etc are integrated organically, the digitalization, visualization and humanization of the ultrasonic-testing are realized, and a well foundation to realize the picturization, intelligentization, automatization of ultrasonic-testing, the quantity and quality analyses of defects is established. The ultrasonic-testing virtual instrument adopts the structure of ultrasonic-testing card and ultrasonic-testing virtual instrument software, which has the merits of simple structure, mighty function and high ratio of performance to cost. The instrument has functions of the setting of ultrasonic-testing parameter ( programme-controlled amplifier's gain, demodulating mode, filtering frequency, ultrasonic emission repeating frequency, sampling start point, sampling length etc.) and the software controlling of ultrasonic testing process. Thus the instrument can adopt different working mode according to its testing condition. The instrument has a sampling rate of 40MHz with 8 bit precision and 64KB high-speed SRAM on the card, which has meet the requirement of common industrial ultrasonic-testing. The software of the ultrasonic-testing virtual instrument is consisted of the device driver of the ultrasonic-testing card and the ultrasonic-testing virtual instrument application software. Using WinDriver to develop the card's device driver can decrease the difficulty of the design and shorten the design cycle time. The appliance software is developed by the soft environment of LabWindowsCVI, which integrate many algorithm of digital signal processing and image processing to process the collected scanning date. It realized the A scanning and established a well foundation for B and C scanning.