循环平稳声场的声源定位研究

摘要

The conventional planar near-field acoustic holography technology cannot exactly refecact the modulation characteristics of cyclostationary sound field radiated from the rotating machineries,and the spurious energy distribution of sidebands exists in its hologram.When the cyclic spectral density（CSD）,instead of the energy spectrum of sound pressure is adopted as a reconstructed physical quantity,the modulating wave and carrier wave components of the cyclostationary sound field can be extracted exactly.Focusing on the complicated nature of calculation and the accuracy of feature extracting,the CSD gathering slice method is proposed,and the effect of the additive white noise on the reconstruction is analyzed.The results of the simulation and experiments show that the method has the better anti-noise performance and sound source can be localized exactly.%旋转机械产生的辐射声场具有循环平稳特性,传统的平面近场声全息技术无法准确反映其调制特性,往往在边频带上出现虚假的能量的分布.采用循环谱密度取代功率谱密度作为重建物理量,则可准确提取循环平稳声场的调制和载波信息.考虑到循环谱密度的计算量以及特征提取的准确性,提出了循环谱密度组合切片分析法,并分析了加性白噪声对重建的影响.仿真分析及实验结果表明,此方法有较强的噪声抑制能力,全息重建的结果可准确反映声源的位置.