基于共振峰的超声空化声发射信号分析

Formant method applied to analyze acoustic emission signals from ultrasonic cavitation

为简单有效地提取超声空化时频信息而估计空化强度,提出应用基于全极点线性预测编码模型的共振峰分析方法,分析19 kHz超声作用下的空化场的声发射信号。将共振峰分析结果与常用的频谱分析和短时傅里叶分析结果进行了对比,发现共振峰分析方法更能从超声空化声发射信号中提取出简单但关键的时频信息。采用共振峰方法的分析结果表明,可以利用空化声发射的共振峰参数如基频频率和相对高频共振峰的幅值来分别反映超声空化的非线性振荡和瞬态空化,进而估计超声空化的强度。

To extract the time-frequency information of ultrasonic cavitation and estimate the intensity of the cavitation simply and effectively, the formant method based on all-poles linear predictive coding model was introduced and applied to analyze the acoustic emission signals of a cavitation field caused by 19 kHz ultrasound. The comparison study shows that it is more capable of extracting simple but important time-frequency information from the acoustic emission signals than the commonly used spectrum method and short time the signals＇ formant analysis shows that some formant parameters frequency and higher frequency formant＇s amplitude, can be oscillation and transient cavitation, thus to estimate the intensity Fourier Transformation （STFT） method. The results of of the acoustic emission signals, such as the fundamental used to describe the ultrasonic cavitation＇s nonlinear of ultrasonic cavitation.