Sub-1 GHz Network-Based Wireless Bridge-Monitoring System: Feature and Verification

Traditional bridge monitoring systems often require wired connections between sensors, a data acquisition system, and data center. The use of extension wires, conduits, and other costly accessories can dramatically increase the total cost of bridge monitoring. With the development of wireless technologies and the notable cost benefits, many researchers have been integrating wireless networks into bridge monitoring system. In this study, a wireless bridge monitoring system has been developed based on the Sub-1 GHz network. The main functional components of this system include sensors, wireless nodes, gateway and data center. Wireless nodes can convert analog signals obtained from the sensors to digital signals, then transmit the collected data to the gateway using the Sub1 GHz network. The gateway receives and sorts data from different wireless nodes and then forwards these data to the data center wirelessly. All collected data are processed in the data center using the data processing software developed in this study. In order to validate the performance of the wireless system developed in this study, a steel girder bridge was monitored in the field during the concrete deck construction. The field results were also compared with the theoretical values obtained from finite element models to ensure the accuracy and reliability of the wireless system. The results indicate that the wireless bridge monitoring system developed in this study is effective and affordable. The Sub-1 GHz network can be a better solution for bridges with complicated site conditions because of the extended data transmission distance. Although the power consumption can be controlled by using low-power consumption components, including the power control in software design can also dramatically reduce the system’s power consumption.