基于时差法的复杂转子系统声发射源定位算法

Acoustic Emission Source Localization Algorithm for Complex Rotor System Based on Time Difference Method

在复杂转子系统的碰摩声发射源定位中,常规的广义互相关时延估计算法难以得到准确的时延值,进而无法进行准确定位。针对这一问题,引入基于平滑相干变换(Smoothed Coherence Transform, SCOT)的双加权二次互相关时延估计算法,计算声发射源信号的到达时间差;再利用Hilbere差值法对相关峰值进行锐化,减小在碰摩过程中噪声的干扰,以获得较为精确的时延估计结果;最后使用得到的时延值进行声发射源定位。实验结果表明,与常规的广义互相关算法相比,该算法对复杂转子系统碰摩声发射源定位具有较高的定位精度。

In the localization of the rub-impact acoustic emission source of a complex rotor system,it is difficult to obtain accurate delay value by conventional generalized cross-correlation delay estimation algorithm,and thus cannot be accurately located.To solve this problem,a double-weighted quadratic cross-correlation delay estimation algorithm based on smoothed coherence transform(SCOT)is introduced to calculate the arrival time difference of the acoustic emission source signal.Then,the Hilbert difference method is used to sharpen the relevant peaks and reduce the noise interference during the rub-impact process,so as to obtain more accurate delay estimation results.Finally,the obtained delay value is used for acoustic emission source localization.Experimental results show that compared with the conventional generalized cross-correlation algorithm,the proposed algorithm has high accuracy for the localization of rub-impact acoustic emission sources in complex rotor systems.