少量测点条件下提高结构法向振速重建精度和分辨率的方法

为了解决少量测点条件下利用近场声全息技术重建结构表面法向振速精度和分辨率不高甚至失效的问题,提出了一种基于声压声辐射模态的全息面插值算法,可有效提高结构法向振速重建精度和分辨率。计算全息面声压声辐射模态向量;根据声压声辐射模态收敛性,求取截断声压声辐射模态展开系数的最小二乘解或Tikhonov正则化解,由此计算出插值点处的声压值;利用插值后的全息面数据重建结构表面法向振速。简支平板激励仿真和音箱实验均表明,少量测点条件下利用该方法能够有效提高结构法向振速重建精度和分辨率,验证了方法的有效性。同时音箱实验验证了方法的可行性。

Method of improving accuracy and spatial resolution of structure normal velocity reconstruction with a small amount of measurement points

Under condition of a small amount of measured pressure data,to solve the problem of low structure surface normal velocity reconstruction accuracy and resolution or even reconstruction failure using near field acoustic holography technology,a holographic surface interpolation algorithm based on the acoustic radiation modes that can effectively improve the structure normal velocity reconstruction accuracy and resolution is proposed.Firstly,the acoustic radiation modal vectors of holographic surface are calculated;Then,according to the convergence of pressure acoustic radiation modes,the least square solution or Tikhonov regularization solution of the truncated expansion coefficient of pressure radiation modes is obtained,and the pressure values of the interpolated point can be calculated;Finally,the structure surface normal velocity is reconstructed by the interpolated hologram data.Both the simple supported plate simulation and the speaker experiment show that the proposed method can effectively improve the reconstruction accuracy and resolution of the normal velocity of the structure surface with a small quantity of known pressure values,and the effectiveness of the proposed method is verified.Meanwhile,the feasibility of the method is verified by the speaker experiment.