Department of Civil Engineering and Engineering Mechanics, Columbia University, New York, NY 10027, USA.
Toshiba, Corporate Research & Development Center, Toshiba Corporation, Tokyo 105-0023, Japan.
Sensors (Basel). 2022 May 22;22(10):3916. doi: 10.3390/s22103916.
Recently, vibration-based monitoring technologies have become extremely popular, providing effective tools to assess the health condition and evaluate the structural integrity of civil structures and infrastructures in real-time. In this context, battery-operated wireless sensors allow us to stop using wired sensor networks, providing easy installation processes and low maintenance costs. Nevertheless, wireless transmission of high-rate data such as structural vibration consumes considerable power. Consequently, these wireless networks demand frequent battery replacement, which is problematic for large structures with poor accessibility, such as long-span bridges. This work proposes a low-power multi-hop wireless sensor network suitable for monitoring large-sized civil infrastructures to handle this problem. The proposed network employs low-power wireless devices that act in the sub-GHz band, permitting long-distance data transmission and communication surpassing 1 km. Data collection over vast areas is accomplished via multi-hop communication, in which the sensor data are acquired and re-transmitted by neighboring sensors. The communication and transmission times are synchronized, and time-division communication is executed, which depends on the wireless devices to sleep when the connection is not necessary to consume less power. An experimental field test is performed to evaluate the reliability and accuracy of the designed wireless sensor network to collect and capture the acceleration response of the long-span Manhattan Bridge. Thanks to the high-quality monitoring data collected with the developed low-power wireless sensor network, the natural frequencies and mode shapes were robustly recognized. The monitoring tests also showed the benefits of the presented wireless sensor system concerning the installation and measuring operations.
近年来，基于振动的监测技术变得非常流行，为实时评估土木结构和基础设施的健康状况和结构完整性提供了有效的工具。在这种情况下，电池供电的无线传感器可以让我们停止使用有线传感器网络，提供简单的安装过程和低维护成本。然而，像结构振动这样的高速率数据的无线传输会消耗相当大的能量。因此，这些无线网络需要频繁更换电池，这对于那些难以接近的大型结构，如大跨度桥梁来说是一个问题。这项工作提出了一种适用于监测大型民用基础设施的低功耗多跳无线传感器网络来解决这个问题。所提出的网络采用低功耗的无线设备，在 sub-GHz 频段工作，允许远距离数据传输和通信超过 1 公里。通过多跳通信实现大面积的数据采集，传感器数据由相邻传感器采集和重新传输。通信和传输时间同步，并执行时分通信，根据无线设备的情况，在不需要连接时让其进入休眠状态，以消耗更少的功率。进行了现场实验测试，以评估所设计的无线传感器网络收集和捕获大跨度曼哈顿大桥加速度响应的可靠性和准确性。得益于用开发的低功耗无线传感器网络收集的高质量监测数据，稳健地识别了自然频率和模态形状。监测测试还展示了所提出的无线传感器系统在安装和测量操作方面的优势。
