Conference_programme: 21.1 - Source localization and acoustic array processing
Lecture: Inverse scheme for acoustic source localization in 3D
Author(s): Gombots Stefan, Kaltenbacher Manfred, Kaltenbacher Barbara
Summary:
Acoustic source localization techniques in combination with microphone array measurements have become an important tool in the development of new products. Moreover, these techniques can be used for failure diagnosis and monitoring as well as for sound design or noise reduction tasks. Thereby, a common technique is acoustic beamforming. It is used to determine source locations and distributions, measure acoustic spectra for complete models and subcomponents, and project results from the array to far field points. The fundamental processing method, Frequency Domain Beamforming (FDBF) is robust and fast, but the resolution and the dynamic is limited. To overcome these drawbacks, one can use deconvolution techniques, e.g. DAMAS, Clean-SC. However, main restrictions are given by simplified source models and describing the transfer function between source and microphone signal using Green’s function for free radiation. Therefore, reflecting (or partially reflecting) surfaces are not really considered, and the method of using mirror sources is quite limited. To overcome these limitations, we propose an inverse scheme based on a constrained minimization problem. In the provided inverse scheme a cost functional is minimized such that the Helmholtz equation with source terms is fulfilled. This approach aims at finding the position and strength of all sources. The reconstruction is based on solving the corresponding partial differential equation in the frequency domain (Helmholtz equation) by applying the Finite Element Method (FEM) considering the actual boundary conditions as given in the measurement setup. To recover the source location the inverse scheme utilizes a sparsity promoting Tikhonov functional to match measured (microphone signals) and simulated pressures. The applicability and the additional benefit of the inverse scheme compared to frequency domain beamforming will be demonstrated.
Corresponding author
Name: Mr Stefan Gombots
e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
Country: Austria
