R. B. Annis School of Engineering, University of Indianapolis, Indianapolis, IN 46227, USA.
Sensors (Basel). 2021 Oct 21;21(21):6988. doi: 10.3390/s21216988.
Real-time monitoring on displacement and acceleration of a structure provides vital information for people in different applications such as active control and damage warning systems. Recent developments of the Internet of Things (IoT) and client-side web technologies enable a wireless microcontroller board with sensors to process structural-related data in real-time and to interact with servers so that end-users can view the final processed results of the servers through a browser in a computer or a mobile phone. Unlike traditional structural health monitoring (SHM) systems that deliver warnings based on peak acceleration of earthquake, we built a real-time SHM system that converts raw sensor results into movements and rotations on the monitored structure's three-dimensional (3D) model. This unique approach displays the overall structural dynamic movements directly from measured displacement data, rather than using force analysis, such as finite element analysis, to predict the displacement statically. As an application to our research outcomes, patterns of movements related to its structure type can be collected for further cross-validating the results derived from the traditional stress-strain analysis. In this work, we overcome several challenges that exist in displaying the 3D effects in real-time. From our proposed algorithm that converts the global displacements into element's local movements, our system can calculate each element's (e.g., column's, beam's, and floor's) rotation and displacement at its local coordinate while the sensor's monitoring result only provides displacements at the global coordinate. While we consider minimizing the overall sensor usage costs and displaying the essential 3D movements at the same time, a sensor deployment method is suggested. To achieve the need of processing the enormous amount of sensor data in real-time, we designed a novel structure for saving sensor data, where relationships among multiple sensor devices and sensor's spatial and unique identifier can be presented. Moreover, we built a sensor device that can send the monitoring data via wireless network to the local server or cloud so that the SHM web can integrate what we develop altogether to show the real-time 3D movements. In this paper, a 3D model is created according to a two-story structure to demonstrate the SHM system functionality and validate our proposed algorithm.
实时监测结构的位移和加速度为不同应用领域的人员提供了重要信息，例如主动控制和损伤预警系统。物联网 (IoT) 和客户端网络技术的最新发展使得带有传感器的无线微控制器板能够实时处理与结构相关的数据，并与服务器进行交互，以便最终用户可以通过计算机或移动电话中的浏览器查看服务器的最终处理结果。与基于地震时峰值加速度提供警报的传统结构健康监测 (SHM) 系统不同，我们构建了一个实时 SHM 系统，该系统将原始传感器结果转换为所监测结构三维 (3D) 模型上的运动和旋转。这种独特的方法直接从测量位移数据显示整体结构动态运动，而不是使用力分析（例如有限元分析）来静态预测位移。作为对我们研究成果的应用，可收集与结构类型相关的运动模式，以进一步交叉验证传统的应力应变分析得出的结果。在这项工作中，我们克服了实时显示 3D 效果所存在的几个挑战。从我们将全局位移转换为元素局部运动的算法中，我们的系统可以在传感器监测结果仅提供全局坐标位移的情况下，计算每个元素（例如柱子、梁和地板）在其局部坐标处的旋转和位移。在考虑同时最小化总体传感器使用成本和显示基本 3D 运动的同时，提出了一种传感器部署方法。为了实现实时处理大量传感器数据的需求，我们设计了一种新颖的传感器数据保存结构，其中可以呈现多个传感器设备之间的关系以及传感器的空间和唯一标识符。此外，我们构建了一种可以通过无线网络将监测数据发送到本地服务器或云的传感器设备，以便 SHM 网络可以集成我们共同开发的内容来显示实时 3D 运动。在本文中，根据一个两层结构创建了一个 3D 模型，以演示 SHM 系统的功能并验证我们提出的算法。
