Automated algorithm for impact force identification using cosine similarity searching

Abstract

A similarity searching technique is adopted to identify the impact force applied on a rectangular carbon fibre-epoxy honeycomb composite panel. The purpose of this study is to simultaneously identify both the location and magnitude of an unknown impact using the measured dynamic response collected by only a single piezoelectric sensor. The algorithm assumes that a set of impact forces are concurrently applied on a set of pre-defined locations. However, the magnitude of all the impact forces except one is considered to be zero. The impact force at all potential locations is then reconstructed through an l2-norm-based regularisation via two strategies: even-determined approach and under-determined approach. In an evendetermined approach, the reconstruction process is performed independently for each pair of sensor and potential impact location. However, in an under-determined approach, the captured vibration signal is the superposition of the responses of the simultaneous 'assumed' impacts at the potential locations. Using either approach, a reconstructed impact force is obtained for each potential impact location. The reconstructed impact forces at spurious locations are expected to have zero magnitude as no impact has actually occurred at these locations. However, there might

An adaptive soft sensor deterioration evaluation and model updating method for time-varying chemical processes

“…Additionally, high-dimensional auxiliary variables in chemical processes result in highly complex models and often incomplete model structures [56]. The moving window method can obtain the latest data representing the current process [57] and adaptively update that data [58], and the cosine similarity correlation calculation method can effectively measure the correlations between vectors [59] and identify the effectiveness of the influences [60]. Therefore, a sample data updating method using moving window--cosine similarity-based soft sensor modeling is proposed to update the sample datasets of soft sensor models for chemical processes and improve their prediction performance.…”

A hierarchical method for the impact force reconstruction in composite structures

“…The aim of this research work was to recover the impact force from Eq. (11). As described in [4], a discrete problem must be solved by transforming the convolution integral [Eq.…”

“…As described in Section 2, it was possible to identify the impact location using the TR method [Eq. (11)]. The transfer function at the impact location can then be obtained by using an interpolation of transfer functions associated with the cell whose vertices are the four calibration points surrounding the impact location.…”

Performance Comparison of Collaborative-Filtering Approach with Implicit and Explicit Data

“…After becoming vectors, the similarity between users (and also items) can be calculated by measuring distances between vectors using well-known metrics, such as cosinesimilarity and Pearson coefficient correlation. The greater the value of the similarity of the vectors, the items (or users) are seen as more relevant to other users (or items) [17], [18], [19].…”