稀疏采样单测量面相干声场分离机理及方法研究

Study on the separation mechanism and method of sound field in single measurement surface with sparse sampling

为改进目前等效源法声场分离技术中存在的测点数目多、适用范围小等问题,提出一种稀疏采样方法分离相干声场。该方法首先对等效源强与重建面声压之间的传递矩阵进行奇异值分解,获取声场的一组稀疏基;然后通过等效源强建立起全息面上测量声压和测量法向振速与系数向量之间的关系;最后通过稀疏正则化求解系数向量的解,从而求出声场的分离声压和分离法向振速。数值仿真分析结果表明:在测量点数较少的情况下,该方法相对于单全息面等效源法具有更高的分离精度;同时,该方法提高了等效源向量的稀疏度,扩大了声场分离的频率范围,在较高频率下仍然具有良好的分离精度。

A sparse sampling method is proposed to separate the coherent sound field to improve the problems of large number of measurement points and small range of application in the current equivalent source sound field separation technology.Firstly,the transfer matrix between the equivalent source strength and the reconstructed surface sound pressure is decomposed by singular value to obtain a set of sparse basis of the sound field,and then the relationship between the measured sound pressure and the measured normal vibration velocity on the holographic surface is established by using the equivalent source strength.Finally,the solution of the coefficient vector is solved by sparse regularization,so as to obtain the separated sound pressure and the separated normal vibration velocity of the sound field.Numerical simulation analysis shows that the proposed method has higher separation accuracy than the single holographic surface equivalent source method with few measurement points.Meanwhile,the proposed method improves the sparsity of the equivalent source vector,expands the frequency range of the sound field separation,and still has good separation accuracy at higher frequencies.