Research On Reconstruction And Separation Of Transient Planar Sound Source Sound Field Based On Iteratively Reweighted

Acoustic source identification is an important premise for noise source control.Near-field acoustic holography（N AH）measured by microphone array is an effective means for identifying the location of the acoustic source and visualizing its sound field.In NAH,the reconstructed pressure can be obtained directly by hologra m pressure or indirectly by solving an intermediate quantity.However,there is an inverse process that usually exists in the direct and indirect reconstruction processes of NAH will lead to a serious instability problem of the solution.Tikhonov regularization is a common technology to be employed in the reconstruction process of N AH fo r suppressing this instability.But the Tikhonov regularization method requires the selection of regularization parameters at each moment of the solution process,and the parameters cannot be guaranteed to be reasonable at each moment.The reconstruction will become less effective.Sparse approaches based on compressive sensing are gradually developed for handling this kind of ill-posed acoustic inverse problem over recent years.In this paper,in the context of the study of NAH based on CS theory,an iterative reweighted-based real time acoustic holography（IR-RTNAH）reconstruction of transient sound fields is proposed for solving inverse p roblems in real-time acoustic holography（RTNAH）.In the inversion of time domain plane wave superposition method（TDPWSM）will lead to error accumulation,an iterative reweighted-based TDPWSM（IR-TDPWSM）is proposed for reconstruction the transient sound field.Considering the application of NAH in non-free fields,a transient sound field separation method based on iterative reweighting of double-sided sound pressure measurement is proposed to achieve the separation of target and interference sound sources.The following are the details of the study contents in this paper.In chapter 1,first introduces the research background and significance of the NAH technique,and then details the current state of research on compressed sensing technology in stationary and transient sound fields,and the development process of NAH in non-free fields.Some of the problems that exist in these applications in NAH are analyzed,and the research content of this paper is identified.In chapter 2,IR-RTNAH is proposed to address the problem of low reconstruction accuracy of RTNAH in the sound field reconstruction process.The reconstruction effect of IR-RTNAH is verified through simulations and experiments,and comparing to the RTNAH with Tikhonov regularization and YALL1.The effect of parameters such as signal-to-noise ratio（SNR）,hologram plane position and iterative initial valueε₀ on the method is further discussed.In chapter 3,IR-TDPWSM is proposed to address the problem that cumulative errors occur in the TDPWSM reconstruction process,and the sound field reconstruction of transient planar sound sources is realized.The feasibility of the IR-TDPWSM is verified by simulations of the excitation plate sound source,and the experimental validation was carried out.The advantages of the method are verified by comparing to the TDPWSM with Tikhonov regularization.The effects of the number of samples in the wave number domain and SNR are discussed.In chapter 4,considers the presence of interfering sound sources in the sound field the CS theory is applied to the sound field separation of double-sided sound pressure measurement,and an iterative reweighted sound field separation method is proposed.The separation effect is verified by simulation,and compared with the double-sided sound pressure sound field separation method with Tikhonov regularization.In chapter 5,summarizes the research work and results of this paper in NAH,and prospects the problems that need to be solved.