Evaluation of the applicability of ble-based wireless sensor networks for operational modal analysis

Abstract

This work evaluates experimentally the applicability of wireless sensors networks (WSNs) based on Bluetooth Low Energy (BLE) for operational modal analysis (OMA) in machine diagnostics. OMA enables the dynamic properties of a mechanical system to be determined based on vibration measurements. A WSN for collecting such measurements requires precise synchronization, the transfer of relatively large volumes of data, and a lifetime of several days or weeks. The higher data rate of BLE 5 (2 Mbps), compared to other prominent radio technologies used in WSNs, offers several advantages, e.g. it could allow a reduction in the overall radio utilization, which generally contributes the most to the power consumption of a sensor node. However, the reliability of BLE 5 links in a machine environment must be assessed to determine the applicability of this radio technology in OMA. This work presents experimental results on the quality of BLE 5 links operating inside an industrial machine which indicate that such links can operate reliably when using a relatively high transmission power (above 0 dBm).