Energy-efficient and fault-tolerant structural health monitoring in wireless sensor networks

Wireless sensor networks (WSNs) have become an increasingly compelling platform for structural health monitoring (SHM) due to relatively low-cost, easy installation, etc. However, the challenge of effectively monitoring structural health condition (e.g., damage) under WSN constraints (e.g., limited energy, narrow bandwidth) and sensor faults has not been studied before. In this paper, we focus on tolerating sensor faults in WSN-based SHM. We design a distributed WSN framework for SHM and then examine its ability to cope with sensor faults. We bring attention to an undiscovered yet interesting fact, i.e., the real measured signals introduced by faulty sensors may cause an undamaged location to be identified as damaged (false positive) or a damaged location as undamaged (false negative) diagnosis. This can be caused by faults in sensor bonding, precision degradation, amplification gain, bias, drift, noise, and so forth. We present a distributed algorithm to detect such types of faults, and offer an online signal reconstruction algorithm to recover from the wrong diagnosis. Through simulations and a WSN prototype system, we evaluate the effectiveness of our proposed algorithms.