MUSIC algorithm based impact localization in the near-field of composite structure

To improve the location precision of foreign object impact in the near-field, the multiple signal classification (MUSIC) based localization algorithm was presented for the impacts estimating. Firstly, classical far-field MUSIC algorithm was extended to near-field version using the Fresnel approximation. Then Gabor transform was applied to extract the narrow-band signal at a center frequency from the impact signal. After scanning over the whole interest direction of the structure, the signal source parameters including range and direction from the peak of spatial spectrum were obtained. The experiment on the epoxy laminates plate was established to verify the validity of the proposed method. Results show that the distance error and the direction error are less than 0.94 cm and 1?, respectively.