镜像地波束形成声源识别方法  

Mirror-ground Beamforming Method of Acoustic Source Identification

作　　者：褚志刚[1,2] 沈林邦 杨洋[3] 

机构地区：[1]重庆大学机械传动国家重点实验室,重庆400044 [2]重庆大学机械工程学院,重庆400044 [3]重庆工业职业技术学院汽车工程系,重庆401120

出　　处：《应用基础与工程科学学报》2015年第1期162-171,共10页Journal of Basic Science and Engineering

基　　金：中央高校基本科研业务费资助项目(CDJZR13110001);国家自然科学基金项目(50975296)

摘　　要：为了消除波束形成声源识别时地面反射对声源识别结果的影响,给出了基于除自谱的互谱成像函数的镜像地波束形成方法.以半圆形阵列为例,基于传统波束形成方法和镜像地波束形成方法模拟的结果表明,低频时镜像地波束形成声源主瓣近似呈圆形,更接近真实声源形状,在中高频处镜像地波束形成方法相对于传统波束形成方法旁瓣水平被有效衰减,声源定位精度更高.进一步,研究了传统波束形成方法和镜像地波束形成方法在地面不同吸声特性情况下的声源识别性能,结果表明,当吸声系数较低时,镜像地波束形成仍能有效识别声源,当地面的吸声系数较高时,镜像地波束形成方法的声源识别性能变差.最后基于扬声器声源的算例试验验证了上述模拟仿真结论的正确性及镜像地波束形成在识别实际声源时的有效性.In order to eliminate the influence of ground reflection on beamforming acoustic source identification results, a mirror ground beamforming method based on cross-spectra imaging function with auto-spectra exclusion was provided.For semicircular array, the simulation results by traditional beamforming method and mirror ground beamforming method show that the shape of the mainlobe by mirror ground beamforming method looks like round shape, even close to the true source shape in low frequency;however, compared with traditional beamforming method, the mirror ground beamforming method in middle and high frequency can effectively attenuate sidelobe level and increase the accuracy in source location. Further studies on different ground sound absorption characteristics on two methods were conducted and the results showed that the mirror ground beamforming method could still identify the sound source effectively in the low absorption coefficient while its performance in the high absorption coefficient was deteriorated. Finally, the experiments with the known loudspeaker source validate the correctness of the simulation and the effectiveness of the mirror ground beamforming method in practical application.

关 键 词：声源识别 波束形成 地面反射 镜像地 

分 类 号：TB52[理学—物理]