Research On The Method Of Underwater Structure Noise Source Location Based On Sparse Reconstruction

The location of noise source is a prerequisite for effectively control noise.Acoustic focusing beamforming technology and near-field acoustic holography technology is a more widely used technology in the field of noise source location.Near-field acoustic holography has a higher resolution than acoustic focused beamforming,but it is limited in high-frequency applications.Because the traditional method is constrained by the Nyquist sampling law,resulting in a waste of hardware resources.Especiall in the structural sound source localization problem,making the deployment becomes more difficult.Compression sensing(CS)breaks through the Nyquist sampling law and compresses the signal during the sampling phase.So it provides a new idea for the location of noise source.In this dissertation,we studies the sparse representation of signals and investigates the method of noise suource localization based on CS.Firstly this paper introduces the CS theory.Then,because of spatial distribution of point sources sparsity,we studied the noise sources localization algorithm based on CS.Finally,simulation is carried out.However,in the near-field case,there are few cases that can be assumed as point sources.Therefore,it is more practical to apply CS-based to structure sources localization.In many literatures,noise sources localization research is separated from structural acoustic radiation,so it is difficult to give convincing results.In this paper,the noise sources localization is combined with the structural acoustic radiation,and the transmission relationship is given by studying the structural acoustic radiation.The receiving data of the measurement array is constructed by using the transfer relationship.In this paper,a finite-length cylindrical shell is taken as an example,and the sound field excited by the excitation is constructed based on the thin shell theory.In the calculation of sound field,the modal method is adopted,and the simulation results are compared with the comsol simulation results.It is found that the modal displacement of every order of the shell surface is sparse when studying the vibrational sound radiation of the shell.Therefore,it is feasible to apply the compressive sensing method to locate the sound sources of the structure.Finally,the simulation results show that the CS method can obtain better reconstructed results with fewer sensors.The research shows that the reconstruction result based on CS has the closest relationship with the performance of the measurement matrix.As to which reconstruction algorithm is more influential on the computational complexity.In the study of structural sound source localization,the feasibility of applying CS method is proposed in combination with the sparsity of modal of displacement.However,as the modal of displacement is reconstructed from the measured sound pressure,the noise wound not be removed,resulting in erroneous modal of displacement.When the surface acoustic field distribution is calculated from this erroneous modal of displacement,the error magnified.Therefore,the proposed method is only suitable for high SNR.