改进匹配追踪法在导波检测信号处理中的应用

摘要

Matching pursuit method based on differential evolution (DE) Algorithm is presented to process ultrasonic guided-waves testing signals. The Gaussian modulated functions is chosen as matching atoms, whose time-frequency characteristics agree well with that of ultrasonic guided-wave signals. DE Algorithmis employed to improve parameters searching efficiency, and cross-term free time-frequency distribution (TFD) is achieved by superimposing the Wigner-Ville distribution (WVD) of each matching atom decomposed. The processed results of the testing signals show that, matching pursuit based on DE algorithm can greatly improve parameters searching efficiency, and the defects discrimination can be achieved from echo signals by TFD characteristic comparison.%提出了基于差分进化算法的改进匹配追踪方法,对超声导波无损检测信号进行处理.选取与超声导波回波信号时频特性相近的高斯调制余弦信号作为匹配原子,利用差分进化算法提高全局参数寻优的计算效率,通过叠加每个匹配原子分量的Wigner-Ville分布得到无交叉干扰项的时频分布.实验检测信号处理结果表明,该方法极大提高了参数搜索效率,通过时频分布特征对比可以有效地从回波信号中实现缺陷辨识.