基于超声相控线阵的缺陷全聚焦三维成像

在无损检测领域,缺陷三维成像能够还原材料内部缺陷的空间信息,与传统的二维成像相比有着明显的优势。目前实现超声相控阵缺陷三维成像主要依靠面阵探头,而这些设备往往十分复杂和昂贵。通过采取适当的数据采集方法和后处理成像算法,超声相控线阵系统能够实现低成本、高效率的三维超声检测成像。采用断层扫描和全矩阵捕捉的方法获取成像数据;再利用全聚焦成像算法绘制高分辨率的断层图像;根据这些图像在三维空间中真实的位置关系,插值还原出缺陷的三维图像。此外,针对全聚焦成像算法计算量大的问题,提出了一种加速算法。实验表明,这种检测方法能够快速得到目标空间区域的高质量三维图像,准确体现缺陷的空间分布情况,相比于借助B扫查图像和C扫查图像材料内部缺陷的方法,具有更强的直观性。

Three dimensional total focus imaging based on ultrasonic linear phased array

In the field of nondestructive testing,three-dimensional imaging has obvious advantages over traditional two-dimensional imaging because it can restore the detail of the flaws inside the material.Three-dimensional imaging with phased array ultrasonic technology has been realized by using matrix arrays,but the equipments can be quite expensive and complex.This paper focuses on the three-dimensional imaging with a linear phased array ultrasonic system,and provides a low-cost and efficient method to generate high quality three-dimensional images. In this method,tomoscan and Full Matrix Capture are used to acquire the data,and then high resolution images of the slices are generated by Total Focus Method,and an acceleration algorithm is proposed to optimize the time-consuming process during TFM.Finally,three-dimensional image is generated by spatial interpolation based on the real locations of the tomograms.An experiment is conducted to validate the approach,and the imaging result is compared with the real flaw distribution inside the aluminum block quantitatively.The experiment demonstrates the effectiveness of the imaging method and the acceleration algorithm.With this method,testing personnel can evaluate the real situation inside the unit under test directly,rather than referring to the B-scan and C-scan images.