波叠加联合波束形成的局部声场重建技术研究

传统近场声全息是以快速傅里叶变换为基础的,在有限测量孔径条件下将产生窗效应和卷绕误差,因此一定程度上制约了其在工程上的应用。基于此,提出了一种基于波叠加联合波束形成的局部声场重建技术。首先利用波束形成对传声器阵列采集的声场信息进行分析计算,获得声源的具体位置;然后在该位置配置等效源,并利用迭代算法对局部声场的数据扩展;最后应用扩展后获得的声场数据进行重构。该技术只需要少量的传声器就可以方便快速的实现声场重建。在半消声室内采用两个音箱模拟声源进行研究,实验结果表明:在小测量孔径下该方法可以准确的重构外部声场,拓宽了近场声全息在工程中的应用范围。

Local sound field reconstruction technique based on combined wave superposition and beamforming method

Under condition of finite measurement aperture, the traditional near-field acoustical holography causes window effects and wraparound error since it is based on fast Fourier transformation, and these restrict its widely application in engineering to some extent.In order to overcome these disadvantages, a local sound field reconstruction technique combined wave superposition and beamforming method was proposed.At first, a wave beamforming method was adopted to localize sound source according to the sound pressure acquired from a microphone array; then, a series of equivalent sound sources were collocated around these sound sources; after that, an iterative algorithm was used to expand the local sound pressure; at last, the wave superposition method was applied to reconstruct the sound field based on the expanded sound pressure.The technique would need a small amout of microphones, and it would be easy and fast to realize sound field reconstruction.An experiment was done in a semi-anechoic chamber by using two sound boxes to simulate the sound sources.The results showed that the proposed method can accurately reconstruct a local sound field under condition of small measurement aperture, and widen the application range of near-field acoustical holography in engineering.