针对实际机械设备噪声的非平稳特征带来的成像问题,采用总体经验模态分解(EEMD)方法对噪声信号进行分离,从而获取噪声的非平稳特点;利用高密度传感器阵列,采用近场声全息(NAH)与波束形成(Beamforming)相结合的方法实现瞬态成像。结果表明:使用该方法能够获得非平稳声场空间分布的动态特征,实现对实际机械设备噪声的有效监测。
Aimed at the imaging of the unsteady noise of actual machinery,the ensemble empirical mode decomposition(EEMD)is used to separate noise signal to get its unsteady characteristics.A high-density distributed microphone array is used to collect the noise signal.Nearfield holography and beamforming technology are used for transient imaging.The results show that a series of dynamic images can be acquired by this method,which is useful for monitoring the machinery noise.