基于分布源边界点法的新型近场声全息技术

Novel nearfield acoustic holography based on the distributed source boundary point method

文章提出采用分布源边界点法作为近场声全息变换算法,建立了基于分布源边界点法的新型近场声全息理论,该方法避开了采用边界元法时所存在的复杂的变量插值、奇异积分的处理、特征波数处解的非唯一性处理等问题,具有计算速度快、计算精度高、计算稳定性好等优点;针对重建结果对测量误差的高度敏感性,提出采用Tikhonov正则化方法稳定重建过程,抑制了重建误差的影响;提出新型的半自由声场全息重建和预测方法,解决了存在地面反射的声场的全息重建问题,对音箱源的研究验证了文中方法的可行性和正确性。

The distributed source boundary point method（DSBPM） is proposed to be the transform algorithm of nearfield acoustic holography（NAH）. The theoretical model of the DSBPM based nearfield acoustic holography is established. With the method,some problems are avoided which occurs as the boundary element method（BEM） is used,such as the complicated variable interpolation,the treatment of singular integral and that of nonuniqueness of solution at the characteristic wavenumber. Considering the high sensitivity of the reconstructed results to the measurement errors, the Tikhonov regularization method is proposed to stabilize the reconstruction procedure and restrict the influence of errors. In order to realize the reconstruction of a semi-free acoustic field, a new method is proposed in which the influence of the reflection from the ground is considered. An experiment on a speaker is carried out to validate the feasibility and correctness of the proposed method.