Intelligent monitoring of spatially-distributed cracks using distributed fiber optic sensors assisted by deep learning.

[Display omitted] • Cracks are monitored using distributed fiber optic sensor (DFOS) and deep learning. • A modified You Only Look Once (YOLO) model adequately interprets DFOS data. • Transfer learning is incorporated to improve the accuracy of the deep learning model. • The robustness of the proposed approach is evaluated in different test scenarios. • The mAP@0.5 of detecting spatially-distributed cracks reaches 0.968. Distributed fiber optic sensors (DFOSs) offer unique capabilities for crack monitoring via measuring strain distributions. However, manually interpreting strain distributions is labor-intensive and time-consuming. To address this challenge, this paper presents a deep learning approach for real-time automatic interpretation of strain distributions, aiming at monitoring spatially-distributed cracks. The proposed approach encompasses three key innovations. First, deep learning-based methods are developed to facilitate automatic detection and localization of spatially-distributed cracks. Second, transfer learning is incorporated to overcome the data scarcity issue in training deep learning models. This ensures robust performance even with limited data. Third, a split-and-merge method is developed, enhancing the accuracy of multi-crack detection. To evaluate the performance of the approach, experimental data from various cases were considered. The results demonstrate a mean average precision (mAP) of 0.968 for crack detection. The processing time for a set of DFOS data, containing 10,000 measurement points, was less than 0.05 s. [ABSTRACT FROM AUTHOR]