波束形成旁瓣效应的消除算法研究

Research on side-lobe eliminate algorithm of beamforming

波束形成技术可以通过非接触式的中远距离声压测量,得到机械设备噪声源位置分布及相对强度,但波束形成算法本身存在"旁瓣效应"引入的虚假声源干扰。因此,基于波叠加法提出对波束形成的改进算法,通过在波束形成定位出的噪声源位置处布置等效源,由声压匹配波叠加法和传声器阵列声压反算等效源强度,再由所得各等效源强度,根据波叠加法基本原理在重建面上进行声压重建,进而消除旁瓣效应。仿真与柴油机噪声源试验结果证明改进算法切实有效。

The location and intensity of the noise source can be figured out by beamforming through non-contact measurement, however, the results of beamforming were affected seriously by the side-lobe phenomenon, and the side-lobe indicate ghost source. So an improve algorithm to suppress the side-lobe phenomenon was proposed based on wave superposition method. Pre-localize the noise source by beamforming and set equivalent sources based on the pre-localize result. Figure out the intensity of equivalent source based on wave superposition method and micro-phone array sound pressure. Then re-construct sound pressure on the re-construction plane based on the equivalent source intensity and wave superposition method.The side-lobe was eliminate finally. Simulation and experiment results show that the improve algorithm can suppress the side-lobe phenomenon successfully.