基于椭圆弧扫描转换的超声波无损检测全聚焦算法

Total Focusing Method for Ultrasonic Non-Destructive Inspection of Homogenous Objects Based on Elliptical Arc Scan-Conversion

针对超声波无损检测的全聚焦算法(TFM)处理全矩阵数据耗时巨大的问题,本文基于椭圆弧扫描转换提出了一种单层物体超声波无损检测的新全聚焦算法DEA-TFM.相对于传统全聚焦算法的逆向处理过程,新算法结合计算机光栅图形学中的椭圆绘制算法,解释了全聚焦算法的计算过程实际上是一个正向处理过程;它将结果图像的绘制和生成转化为椭圆弧的扫描转换操作和叠加;同时对原Bresenham椭圆绘制算法进行扩展,提出了绘制二维任意椭圆的改进算法,使新全聚焦算法能够适用于任意形状的相控阵超声波换能器探头.经过仿真实验证明,新算法和传统算法有着相同的运行结果,但是新算法运行速度有一个数量级的提升.

Since it is extremely time-consuming for the traditional total focusing method（ TFM） to process ultrasonic full matrix data,a novel total focusing method based on drawing elliptical arcs（ DEA）,called DEA-TFM,is proposed in this paper. Unlike the reversed computing process of the traditional TFM,DEA-TFM reinterprets the newtotal focusing method in the forward direction to improve its performance. Combined with the generation of elliptic arcs in computer raster graphics,DEA-TFM converts the generation of the result image to scan-conversion operations of multiple elliptical arcs.Besides,based on Bresenham ellipse algorithm,a rendering algorithm applicable to arbitrary elliptic arcs is put forward,making the novel total focusing method suitable for phased array probes in any shapes. The simulation experiments showthat the result images generated by the novel total focusing method,DEA-TFM,are identical to those obtained by the traditional method,but the newtotal focusing method speeds up the imaging process by one order of magnitude.