采用交替投影算法重构超声信号

Ultrasonic signal reconstruction using alternating projection algorithm

建立了超声探测缺陷回波的数学模型,讨论了信号奇异性同其小波变换之间的关系以及通过小波变换模极大值精确重构原信号的原理和方法,利用M a llat的交替投影算法对仿真的超声信号进行了精确重构和对实际检测到的超声信号进行了消噪处理。结果表明,利用小波变换模极大值重构信号的交替投影算法来重构超声信号,重构精度高,实现速度快,用于处理染噪信号,消噪效果好,是一种较为理想的处理超声信号的方法。

In the present paper,the mathematical model of ultrasonic detection flaw echoes was established, the relationship between signal singularity and its wavelet transform, and the principium and method for which the original signal is reconstructed accurately through wavelet transform modulus maxima were discussed. The simulated ultrasonic signal was reconstructed accurately and two ultrasonic signals which were detected in ultrasonic test were de-noised by using Mallat＇s alternating projection reconstruction algorithm. The test result showed that the algorithm given in this paper leads to a high precision for the reconstruction, a quick speed for the performing speed a good effect for the de-noising. So it was a perfect method of dealing with ultrasonic signal.