基于Morlet小波滤波的改进方法及仿真研究

基于Morlet小波的滤波方法是新近发展起来信号分析方法,对于提高结构动态测试信号分析精度具有重要作用.本文对该方法的原理与算法进行了分析,指出该方法分析效率较低,尤其是滤波过程对信号阻尼特性有不利影响等问题.在此基础上,提出了基于Morlet小波滤波的改进方法.采用欧洲航空界广泛应用的GARTEUR飞机模型进行数值仿真研究,利用改进前后两种方法对仿真的扫频信号进行滤波,并基于滤波数据进行阻尼参数的识别.结果表明,改进方法计算量小,且较好地保持了信号的阻尼信息,验证了改进方法的有效性.

An improved Morlet wavelet based signal filtering method and numerical simulation

Morlet wavelet based signal filtering method is a newly-developed signal processing method.The method plays an important role in improving the signal analysis accuracy in the structural dynamic testing.The principle and algorithm are analyzed in detail in paper.The reason why the algorithm is low efficient and the negative effect of filtering on signal damping characteristics are pointed out.An improved signal filtering algorithm is proposed.Numerical simulation is performed to verify the proposed algorithm.GARTEUR aircraft model,which is generally used by Europe aerospace industry,is adopted in the numerical simulation.The simulated sweep signals are filtered by using both of the methods.And,modal frequencies and damping ratios are identified from the filtered signals.The results imply that the proposed algorithm is efficient and able to keep the damping information of the signal.