【摘要】 根据超声无损检测中缺陷和噪声反射回波的瞬时频率的差别,提出利用超声信号瞬时频率在一移动窗内熵的信息,估计缺陷的时频位置。瞬时频率熵方法使得用Wigner-Ville分布表示超声信号时,既能利用Wigner-Ville分布的重要性质,又能实现缺陷的准确定位。对仿真数据和实际探伤数据的实验结果分析表明,瞬时频率熵方法不仅能够识别单个缺陷,也能有效地检测多个缺陷。更多还原

【Abstract】 This paper proposed a method using the information about the entropy of instantaneous frequency to localize the defect in time-frequency domain, which was based on the difference of the instantaneous frequency between defect and noise. Moreover, the proposed method made the defect locating and utilizing the important properties of WVD possible. The experiments with simulated and experimental ultrasonic signals indicate that the proposed method can detect single defect and localize the multiple defects in time-frequency plane reliably.更多还原