联合波束形成和球面谐波逼近法的复合声全息技术研究

Study of Compound Acoustic Holography with Joint Beamforming and Spherical Harmonic Approach

水下航行器的噪声水平将直接影响到其安全,为了有效抑制水下航行器的声学亮点,首先需要找到其声学亮点并了解其辐射噪声的水平。由于水下航行器在航行过程中其姿态不能精确控制,不能在其近场布置传声器,不满足近场声全息的应用条件,为此提出一种联合波束形成和球面谐波逼近法的复合声全息技术,首先利用传声器阵列获取声场的声压信息,采用波束形成法定位声源,然后利用球面谐波逼近法重构声场从而可实现声学亮点定位。采用两个脉动球模型进行仿真计算,并和理论声场进行比较。结果表明,此复合声全息技术能较为准确的对辐射体进行声场重构,由于采用波束形成法进行前处理,使得声场重构中需要的传声器数量减少,可提高实际工程应用效率。

The noise level of underwater vehicle will directly affect its safety. In order to effectively suppress the acoustic highlight of underwater vehicle, it is necessary to find its acoustic highlight and the level of noise. Because the underwater vehicle can not be precisely controlled during navigation and the microphones can not be arranged in the near field. A composite acoustic holography combining spherical beamforming and spherical harmonic approximation technology is presented. Firstly, the sound pressure information of the sound field is obtained by the microphone array. The sound source is located by the beamforming method, and then the sound field is reconstructed by the spherical harmonic approximation method.Two pulsation ball model is used to simulate in the paper, and compared with the theoretical sound field. The comparison shows that this composite acoustic holography can accurately reconstruct the sound field. Because the beamforming method is used for the pre-processing, the number of the microphones used in the reconstruction of the sound field is small, which is convenient for practical application.