Sound Field Reconstruction And Source Identification Technology Based On Compressed Sensing Equivalent Source Method

As one of the reconstruction method of near-field acoustic holography,the equivalent source method has a wide range of applications in real life because of its simple and efficient algorithm,and can be used for the reconstruction of irregular source.However,in the actual measurement,it is found that in order to obtain high-resolution reconstruction image,a large number of sampling points must be arranged,which leads to the increase of sampling cost.Compressed sensing technology points out that as long as the signal is sparse,the original signal can be reconstructed with fewer sampling points.This technology makes up for the deficiency of near-field acoustic holography based on equivalent source method.In this paper,based on the near-field acoustic holography of equivalent source method,a near-field acoustic holography based on compressed sensing equivalent source method is proposed,which can not only reduce the sampling points,but also obtain high resolution reconstruction image.The specific research contents are as follows(1)The development history of near-field acoustic holography is reviewed,and the advantages and disadvantages of various reconstruction method are summarized.(2)The compressed sensing theory is introduced,and the compressed sensing technology is introduced from the sparse representation of the signal,the design of the observation matrix and the reconstruction algorithm.The principle and solving steps of orthogonal matching pursuit are analyzed.(3)The near-field acoustic holography based on compressed sensing equivalent source method is proposed.Two monopole sound sources are reconstructed by the method,and the results are compared with the near-field acoustic holography based on equivalent source method.From the effect of the two reconstruction images,the sound field reconstruction image based on compressed sensing equivalent source method is closer to the theoretical value,the image resolution is higher,and the error is better,It can be seen that the error of the compressed sensing equivalent source method is less than 15% at different frequencies,which is twice as small as that of the equivalent source method.(4)In order to study the near-field acoustic holography based on compressed sensing equivalent source method in detail,the monopole source is identified and located by controlling different parameters,and compared with the traditional equivalent source method,so as to observe the effect of source identification based on compressed sensing equivalent source method.The results show that under different parameters,the equivalent source method based on compressed sensing has accurate sound source recognition effect.(5)In order to verify the practical application effect of the equivalent source method based on compressed sensing,the sources of six loudspeakers are identified and located.The results show that the sources of six loudspeakers can be perfectly identified,and the image resolution is very high.In order to verify that the near-field acoustic holography based on compressed sensing equivalent source method can achieve the purpose of reducing the sampling cost,we further reduce the number of microphones in the linear array.The reconstruction results show that the method fails at 500 Hz,and the effect of source identification is very good at 1100 hz and 2000 Hz,and the image resolution is also very high.It shows that the compressed sensing equivalent source method is feasible and effective.