Group delay based location template matching method for the identification of the impact location on a plate

摘要

The location template matching (LTM) method is occasionally used in the area of structural health monitoring and human-computer interface system when the location of impact on an object is needed to be identified. In general, the LTM method utilizes the cross-correlation (or the correlation coefficient) between two time signals, and its performance is influenced by many factors such as the spatial resolution of the pre-defined reference points, the frequency bandwidth of a signal and the length of data, etc. In addition, the correlation based LTM method often needs many sensors to improve the accuracy of identification. To overcome these disadvantages, a group delay based LTM method (namely G-LTM) is introduced in this paper. Particularly, the proposed method uses the group delay of a fictitious linear time-invariant system as a measure of similarity. The experimental results verify a high quality of the G-LTM method by maintaining 100% accuracy for all the different grid spacing while the accuracy of the correlation based LTM method decreases significantly as the grid spacing becomes smaller.