Deploying wireless sensor networks with fault tolerance for structural health monitoring

Structural health monitoring (SHM) brings new challenges to wireless sensor networks (WSNs) : large volume of data, sophisticated computing, engineering-driven optimal deployment, and so forth. In this paper, we address two important challenges: sensor placement and decentralized computing. We propose a solution to place sensors at strategic locations to achieve the best estimates of geometric properties of a structure. To make the deployed network resilient to faults caused by communication errors, unstable network connectivity, and sensor faults, we present an approach, called FTSHM (fault tolerance in SHM), to repairing the network to guarantee a specified degree of fault tolerance. FTSHM searches the repairing points in clusters and places a set of backup sensors at those points by satisfying civil engineering requirements. FTSHM also includes a SHM algorithm suitable for decentralized computing in energy-constrained WSNs, with the objective to guarantee that the WSN for SHM remains connected in the event of a sensor fault thus prolonging the WSN lifetime under connectivity and data delivery constraints. We demonstrate the advantages of FTSHM through simulations and experiments on a real civil structure.