基于虚拟仪器的回声探伤系统设计与实现

Design and realization of ultrasonic testing system based on virtual instrument

本文介绍了一种应用虚拟仪器技术的回声探伤系统,它由硬件部分和一套控制分析软件组成。文章主要介绍了控制分析软件的各个功能组成部分,其各个功能块相对独立。该系统是一套具有脉冲激励产生,回波信号数据采集,降噪,缺陷定位,缺陷特征提取功能的完整的回声探伤系统。在LabVIEW软件的基础上通过调用第三方数据采集卡的dll库函数进行回波信号的采集,提出了波形和数组抽值相结合的精确定位的方法,提出了一种根据缺陷波形的上升和下降速率来判断缺陷类型的方法。实验结果表明缺陷能够被精确地定位和定性。

This article introduces a kind of ultrasonic testing system based on virtual instrument technical. It is constituted of hardware and a control and analysis software. The article mainly introduces each module of the control and analysis software, and these modules are independence. This system is a set of integrated ultrasonic testing system, which can create a number of stimulation pulses, collect echo signal, realize signal de-noising, locate the defect, and extract the feature of the defect. By calling of the dll database function of the data card base on the LabVIEW software, it realizes the echo signal collecting. In this paper, a method that combines the signal wave with array extraction is presented to locate the defect, it also proposes a method that according to the ascend velocity of the wave and the descend velocity of the wave to judge the type of the defect. The results of experiment indicated that the defect could be located precisely and identified correctly.