Application of Improved ART Algorithm in Concrete Ultrasonic Imaging

摘要

Algebraic Reconstruction Technique (ART) algorithm is the conventional iterative algorithm of concrete ultrasonic CT tomography, it has many shortcomings, such as its calculation accuracy is not high, convergence speed is slow slower, and the peripheral units of abnormal body is affected by abnormal body and so on. An improved algebraic reconstruction technique algorithm based on block iteration is proposed in this paper. The main idea of the new algorithm is to divide the meshes into blocks step by step, and to compute the wave speed of each block by ART algorithm, put the wave speed of next higher level units as the iterative initial value of next lower level units. Do this process until each block can not be divided any more. Through continuous division block unit, finally reach the purpose of rebuilding the structure image of test area in concretes. Computer simulation and concrete model of ultrasonic computerized tomography show that ART algorithm based on block iteration is capable of reconstructing moderate, improving precision of computing, and weakening the influence caused by abnormal area.