Error outlier with weighted Median Absolute Deviation threshold algorithm and FBG sensor based impact localization on composite wing structure

In this paper, a low velocity impact localization algorithm based on an error outlier assessment technique with weighted Median Absolute Deviation (MAD) threshold was developed to localize impact on complex composite structures. The error outlier with MAD threshold algorithm was used to localize impacts on a 1000 mm × 1400 mm area of the upper and lower surfaces of a Jabiru UL-D composite wing. Impact monitoring was performed with three multiplexed FBG sensors and the data acquisition was done using SFI-710 high speed interrogator to obtain the impact response signal at a frequency of 100 kHz. The weighted MAD threshold used to filter the likely impact locations from a set of detected locations, and the proposed algorithm was able to localize impacts with consistent overall performance for a varying number of allowed detected locations. A parametric study was also performed to determine the possibility of localizing impact using a single sensor. The feasibility of utilizing the error outlier with weighted MAD threshold algorithm to localize impact with a single sensor was effectively demonstrated. Overall, impacts on the upper and lower surface of the composite wing were predicted and the localization results for three and one FBG sensors were comparable.