A wireless sensor network for structural health monitoring: performance and experience

While sensor network research has made significant strides in the past few years, the literature has relatively few examples of papers that have evaluated and validated a complete experimental system. In this paper, we discuss our deployment experiences and evaluate the performance of a multi-hop wireless data acquisition system (called Wisden) for structural health monitoring (SHM) on a large seismic test structure used by civil engineers. Our experiments indicate that, with the latest sensor network hardware, Wisden can reliably deliver time-synchronized tri-axial structural vibration data reliably across multiple hops with low latencies for sampling rates up to 200 Hz. This performance was achieved by iteratively refining the system design using a series of test deployments. Our experiences suggested the need for careful onset detection in order to preserve the fidelity of the structure's frequency response. Furthermore, the high damping characteristics of large structures motivated an exploration of the processing, sampling, and communication limits of current platforms.