采用振速测量的改进统计最优近场声全息方法

针对常规统计最优近场声全息在空间多源声场重建过程中所需波函数项数多、重建精度不理想的问题,本文提出了一种基于振速测量的改进统计最优近场声全息算法。与常规算法不同,改进算法主要根据声源特点选取合适的波函数组合来计算声场传递矩阵。通过数值仿真初步验证了该方法的准确性和有效性,并与常规算法进行了详细的对比分析。仿真结果表明,改进算法重建精度高,随频率的变化相对误差波动较小,且随着频率的增大相对误差有逐渐减小的趋势;此外,不同的波函数组合,重建效果差异很大,当选取的波函数与声源共形且数量一致时重建效果最好。

Improved statistically optimal nearfield acoustical holography base on particle velocity measurement

To reconstruct the sound fields generated by multiple spatial sound sources, the conventional statistically optimized near-field acoustical holography(SONAH) needs a large number of higher-order elementary wave functions to represent the sound field, and the results of reconstruction are generally unsatisfactory. In general, it is more efficient to predict the sound fields by using a basis of wave functions that conform to the source shapes and fewer terms are required for an accurate reconstruction than a basis that does not reflect these source properties. In conventional method, a single wave function type is often used to reconstruct the sound fields, while the improved SONAH use a set of elementary wave functions which was selected depending on the features of sound sources to calculate the sound fields transition matrix to reconstruct the sound fields. The improved method can alleviate the need for higher-order elementary wave functions and decrease error. Two sets of numerical simulations are used to demonstrate the validity and applicability of reconstruction by using this improved method. The results show that the proposed method achieves more accurate results than that of the conventional SONAH methods. Moreover, the relative errors have a small disturbance (under 10%) with the frequency of sound sources changing from 200Hz to 2000Hz, which suggests that the improved method has a strong robustness to frequency domain. The selection of the sets of elementary wave functions has a great influence on the accuracy of a reconstruction. It is found that the improved method has an accurate reconstruction when the sets of elementary wave functions are conformal with the sound source shapes and equal to the number of sound sources.