适用于循环平稳声场的基于波叠加法的近场声全息技术

Nearfield acoustic holography based on wave superposition algorithm for cyclostationary sound filed

在原有的平面循环平稳近场声全息基础上,提出一种基于波叠加法的循环平稳近场声全息技术,可以对具有复杂表面的声源进行全息重建,重建的声源表面声压谱相关密度函数能反映出调制信号的信息.声源表面声压谱相关密度函数全息图形象地反映了调制信号在表面的强弱分布情况,可由此确定调制信号源的产生位置.仿真分析和实验验证表明,基于波叠加法的循环平稳近场声全息技术可以更准确地反映循环平稳声场的调制特性.该方法继承了波叠加法的优点,无需计算边界奇异积分,计算效率高、精度好.

The seriously modulated radiation sound waves, as a kind of special nonstationary signal in the engineering, can be considered as cyclostationary. The modulating feature can not be understood clearly via the reconstructed sound field by conventional nearfield acoustic holography （NAH）. A cyclostationary NAH （CYNAH） technique based on wave superposition algorithm （WSA） is suggested for reconstructing the cyclostationary sound field, which can be applied to the cyclostationary acoustic sources with complicated profiles. The information of modulating wave can be understood by the reconstructed hologram of cyclic spectrum density （ CSD）, in which the distribution of modulating wave is visualized and the location of modulating wave can be determined. The simulation and the experiment verified that the modulating characteristic can be understood by CYNAH based on WSA. The main advantages of WSA, including the high calculation accuracy and calculation efficiency due to the exclusion of uniqueness and singularity problems inherent in the boundary element method, are retained in the presented CYNAH procedure.