基于VMD与小波阈值的激光自混合干涉位移信号滤波方法

激光自混合干涉实验信号含有严重的噪声,噪声会对位移的测量产生较大的影响,为了保证位移测量的准确性,提出了基于VMD与小波阈值的滤波方法。利用VMD将信号分解为k个固有模态函数(IMF),对IMF进行小波阈值处理并重构达到滤波的目的。使用插值法结合条纹计数法的原理恢复重构位移信号实现位移的测量。通过仿真对所提方法进行了测试与对比,并结合实验使用绝对误差与标准误差对实际位移与恢复后的位移信号进行比对,结果表明了基于VMD分解与小波阈值的激光自混合干涉位移测量的准确性较高。

Research on laser self-mixing interference displacement signal filtering method based on VMD and wavelet threshold

The experimental signal of laser self-mixing interference contains serious noise,which will significantly influence the measurement of displacement.In order to ensure the accuracy of displacement measurement,a filtering method based on VMD and wavelet threshold is proposed.VMD is used to decompose the signal into k inherent mode functions(IMF),and the IMF is processed by wavelet threshold and reconstructed to achieve the purpose of filtering.The interpolation method,combined with the principle of fringe counting,is used to recover and reconstruct the displacement signal to achieve displacement measurement.The proposed method is tested and compared by simulation.By testing and comparing the methods proposed using stimulation,the absolute error and standard error compare the actual displacement with the recovered displacement signal.The results show that laser self-mixing interference displacement based on VMD decomposition and wavelet threshold is accurate.