A multi-scale strategy in wireless sensor networks for structural health monitoring

Wireless sensor network (WSN) has been considered to be the next generation paradigm of structural health monitoring (SHM) systems due to its low cost, high scalability and flexibility. However, some inherent limitations of WSN such as low-bandwidth wireless communication, limited resources on wireless sensor nodes, must be addressed to meet the generally high requirements of SHM. Distributed in-network processing has been widely accepted as a solution to this problem. However, the drawbacks of existing distributed algorithms, such as the low sensitivity, the dependency on accurate structural model, the incapability of handling various environmental conditions, et al., greatly constrained their practical applications. In this paper, we propose a multi-scale strategy in WSNs for SHM applications. The approach, called the ACF-CCF, utilizes the autocorrelation function of individual sensor node to detect the existence of damage and the cross-correlation function of designated node pairs to obtain damage location. Through simulation and laboratory test, the effectiveness of the proposed approach is demonstrated. Compared with existing distributed SHM algorithms, the method is energy efficient, model free and is robust to various environmental conditions.