Damage Detection in Bridge Structures: An Edge Computing Approach

Wireless sensor network (WSN) based SHM systems have shown significant improvement as compared to traditional wired-SHM systems in terms of cost, accuracy, and reliability of the monitoring. However, due to the resource-constrained nature of the sensor nodes, it is a challenge to process a large amount of sensed vibration data in real-time. Existing mechanisms of data processing are centralized and use cloud or remote servers to analyze the data to characterize the state of the bridge, i.e., healthy or damaged. These methods are feasible for wired-SHM systems, however, transmitting huge data-sets in WSNs has been found to be arduous. In this paper, we propose a mechanism named as ``in-network damage detection on edge (INDDE)" which extracts the statistical features from raw acceleration measurements corresponding to the healthy condition of the bridge and use them to train a probabilistic model, i.e., estimating the probability density function (PDF) of multivariate Gaussian distribution. The trained model helps to identify the anomalous behaviour of the new data points collected from the unknown condition of the bridge in real-time. Each edge device classifies the condition of the bridge as either "healthy" or "damaged" around its deployment region depending on their respective trained model. Experimentation results showcase a promising 96-100% damage detection accuracy with the advantage of no data transmission from sensor nodes to the cloud for processing.