Wireless sensor nodes for generic signal conditioning: Application to Structural Health Monitoring of wind turbines

Abstract

Condition monitoring, fault diagnosis and Structural Health Monitoring (SHM) are an essential part of predictive maintenance. In order to provide early warning of damage, wireless sensor nodes are located at structures, which are often in hostile and hard to access environments. Therefore, there is a need of using sensor nodes with low power signal conditioning electronics, wide range measurement, synchronous data acquisition and reliable signal transmission within large scale-networks.The sensor nodes developed in this work contain a transducer, a signal conditioning circuit and a signal processing software, and are powered by a small rechargeable lithium-ion polymer battery. The signal conditioning circuit is generic and configurable, enabling the conditioning of accelerometers and strain gages, and the signal acquisition of the nodes is performed through wireless synchronized communication.The performance of the presented device is demonstrated for SHM of wind turbines. The commonly used system for SHM of wind turbines is installed during the construction of the structure and consists of wired sensors connected to a central data acquisition unit via cables. In this respect, the system developed in this work, which forms a wireless sensor network (WSN) for SHM, is compared to the commonly used system for SHM of wind turbines. The developed WSN offers two main advantages with respect to commonly used systems for SHM: installation and maintenance cost, and time, high reduction.