基于改进统计最优近场声全息的空间多种声源声场重建

为获取空间多种声源声场信息,传统统计最优近场声全息需要较多高阶项数的波函数来重建声场,而随着波函数阶数的提高,该方法对误差的放大作用也越大;此外传统方法都采用与声源共形的全息测量面,限制了其应用范围。提出了一种基于平面测量的改进统计最优近场声全息方法,可在波函数阶数较低的情况下提高重建精度。首先通过分析空间多种声源的特点选取合适的波函数组合,然后用该组合求出声场传递矩阵,最后重建出目标声源声场。通过数值仿真验证了该方法的有效性和适用性。结果表明:该方法能够有效地降低重建所需波函数阶数,抑制高阶波数对误差的放大作用从而提高重建精度,即使全息面与声源不共形,也能准确地重建出目标声源声场。

Sound field reconstruction of multi-types of spatially sources by improved statistically optimized near-field acoustical holography

To reconstruct the sound field generated by multi-types spatially sound sources,the conventional statistically optimized near-field acoustical holography (SONAH) needs high-order terms to represent the sound field,and the high-order terms are more susceptible to noise contamination.Furthermore,the conventional SONAH is usually required to be conformal with the shape of sound source,and the hologram measurement surface of this technique is usually planar.This paper presents an improved SONAH which can reconstruct the sound field accurately in low-order terms.Firstly,a set of wave functions are selected depending on the features of spatial sound sources.Then,the transfer function matrix is calculated by using the wave function set to reconstruct the sound field.Numerical simulations are used to demonstrate the validity and applicability of this approach.The results show that the number of wave function orders can be reduced and thus the errors caused by high-order terms can be restrained to obtain more accurate results than that by using the conventional SONAH method.The proposed technique can be used to reconstruct the sound field accurately even when the hologram measurement surface is not conformal with the sound source.