基于EMD算法的双外腔激光自混合微振动测量

基于激光自混合理论,提出了一种双外腔激光自混合干涉信号分离的方法,以实现两路微振动的同时测量。用EMD算法对不同频率的两路激光自混合信号进行分离。以原始信号和各IMF分量的互相关系数作为判断依据,选择出高频一路所需的IMF分量。根据两路自混合信号具有线性叠加的性质,原始信号减去高频一路信号即得低频一路信号。对分离出的每一路信号进行频谱分析,利用主频阶次判定法实现振幅重构。结果表明,仿真和实验信号均能有效被分离。

Two-external-cavity laser self-mixing micro-vibration measurement based on EMD algorithm

Based on the theory of laser self-mixing,a two-external-cavity laser self-mixing interference signal separation method is proposed to achieve simultaneous measurement of two-external-cavity micro-vibration.The EMD algorithm is used to separate the two laser self-mixing signals of different frequencies.The correlation coefficient between the original signal and each IMF component is used as the judgment basis,and the IMF component required for the high frequency is selected.According to the linear superposition property of the two-external-cavity self-mixing signal having a linear superposition,the high-frequency signal is subtracted from the original signal to obtain the low-frequency signal.Then,the spectrum analysis is performed on each of the separated signals,and the amplitude reconstruction is realized by dominant harmonic order determination algorithm.The results show that both the simulated and experimental signals can be effectively separated.