基于EEMD的舰船辐射噪声特征提取方法研究

Ships' radiated noise feature extraction based on EEMD

为了解决复杂海洋环境中水声信号的特征提取问题,提出了一种利用集合经验模态分解(EEMD)研究舰船辐射噪声特征提取的方法。对经验模态分解后的不同类别三类舰船辐射噪声信号各阶固有模态函数(IMF)中心频率可分性进行分析,并讨论了最强IMF中心频率特征参数。通过比较一定数量不同类别的舰船辐射噪声的最强IMF中心频率及高低频能量差特征参数发现,同类舰船的特征参数基本处于同一水平,不同类型的舰船存在一定差异。实验结果表明,采用EEMD的舰船辐射噪声信号的最强IMF中心频率作为特征参数相比高低频能量差特征参数对舰船具有较好的可分性。

In order to solve the feature extraction problem of underwater acoustic signals in complex ocean environment,a new method for feature extraction of ships, radiated noise was proposed based on the ensemble empirical mode decomposition（ EEMD） . Three different types of ship radiated noise were chosen to perform the center frequency and energy analyses for their intrinsic mode functions （IMF） . It was shown that the center frequencies of IMF are different from that of the IMF with the highest energy, so the center frequency characteristic parameters of the IMF with the highest energy can be applied to extract ships, radiated noise features. By comparing the center frequency of the IMF with the highest energy and the energy difference between high frequency energy and low frequency one for a certain number of signals of different types ships, radiated noise,it was shown that the center frequency of the IMF with the highest energy is at the same level for similar ships, but there is an obvious difference for different types of ships. The test results showed that the center frequency of the IMF with the highest energy as a characteristic parater is better than the energy difference between high frequency energy and low frequency one befor ships, radiated noise feratute extraction.