REAL-TIME TOTAL FOCUSING METHOD IMAGING FOR ULTRASONIC INSPECTION OF THREE-DIMENSIONAL MULTILAYERED MEDIA

In non-destructive testing of three-dimensional media, the total focusing method (TFM) draws attentions of numerous researchers owing to its ability to provide image with superior quality. But its application in multilayered media is limited by the computation complexity of calculating point of incidence (POI) and increased quantity of acquired ultrasonic data. This paper presents a novel 3D-TFM called linear scan-conversion (LSC) 3D-TFM for the imaging of 3D multilayered media, which uses the scan-conversion algorithm of line segment to substitute traditional ray-tracing method to calculate POI. The iterative computations in ray-tracing method can be avoided, which reduces the time complexity by one order of magnitude. The simulation experiment indicates that LSC 3D-TFM speeds up the imaging process 28 times while maintaining the same result.