Magneto-Inductive Six Degree of Freedom Smart Sensors (MiSixthSense) for Structural and Ground Health Monitoring

用于结构和地面健康监测的磁感应六自由度智能传感器 (MiSixthSense)

• 批准号: EP/M017583/1
• 负责人: Andrew Markham
• 金额: $ 25.12万
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2014
• 资助国家: 英国
• 起止时间: 2014 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FM017583%2F1
• 关键词: Magneto; Inductive; Six; Degree; Freedom

Catastrophic failure of large civil structures like bridges, dams, embankments and buildings can result in fatal, costly and environmentally detrimental consequences. However, failures can also occcur in the surrounding groundwork, for example landslides and subsidence (sinkholes). Structural collapse during construction also poses high risk to people working on construction sites. There is a strong need for a sensing technology that is able to measure the performance of a structure over its entire lifetime, as well as its associated foundations and the surrounding soil and rock supporting the structure. This will help to provide early warning of impending failure, inform repair operations and optimize building methods.The current gold-standard for monitoring structural stress and failure are distributed fibre optic sensors, which use the change in the properties of a thin fibre-optic cable to measure aspects such as strain. However, fibre-optic sensors are essentially wired into the structure, require deployment effort and provide a point of ingress, weakening the integrity of the structure. More importantly though, fibre-optic sensors can only measure strain along the fibre axis, meaning that the three-dimensional shape deformation of the structure cannot be directly measured. Additionally, it is time-consuming and costly to install fibre-optic sensors within the foundations and surrounding soil/rock, limiting their use to high risk projects.This ambitious project seeks to develop a low-cost, wireless, embeddable sensing technology that can measure structural deformations in 3-D from deep within a structure, its foundations and surrounding ground, that are small enough to add to the concrete mix or injected into rock. Not only can each sensor measure changes in its position, it can also measure changes in orientation, yielding a full six degree of freedom sensor. Key to this is the use of low frequency magnetic fields that are able to penetrate rock, soil, concrete and water with minimal loss of signal, a marked advantage over current wireless technology based on high frequency radio that cannot penetrate even a few cm of concrete. These cm-scale, low cost sensors are mixed in with the concrete pour, instantly forming a self-organizing and healing communication network. These devices start monitoring from the moment the element (e.g. a pillar or a beam) is poured, providing information over the entire lifetime of a particular structural element, from the concrete curing process to loading to monitoring cracks and corrosion. When structural elements are placed next to each other, the network will automatically extend to form a larger, merged communication system. The sensors can measure their precise position and orientation within the structure and how this changes over time. With a number of these sensors the actual shape of the structural element and how it is bending or twisting with loads can be sensed. This is currently impossible to achieve using any other distributed sensing technology, a key advantage of low frequency vector fields, having both magnitude and direction in 3-D.One of the issues of embedding sensors within a structure is maintaining operation over the lifetime of the structure, which can be many decades. The sensors use the same low frequency magnetic fields to harvest energy, which is either collected from ambient magnetic fields, such as mains wiring, or directly injected into the metallic reinforcement of the structure. This allows for battery-free, indefinite operation.This technology has the potential to make buildings and large structures truly smart, using low cost, easy to deploy sensors that can operate from within the structure and the surrounding groundwork. This will enable real-time monitoring of key indicators of potential failure over the lifetime of the structure, providing early warning of impending disaster, with potentially life-saving results.

大型土木结构如桥梁、水坝、堤坝和建筑物的灾难性故障可能导致致命的、昂贵的和对环境有害的后果。然而，周围地基也可能发生故障，例如滑坡和沉降（天坑）。建筑期间的结构倒塌亦对在建筑地盘工作的人士构成高风险。强烈需要一种能够测量结构在其整个寿命期间的性能以及其相关基础和支撑结构的周围土壤和岩石的传感技术。这将有助于对即将发生的故障提供早期预警，通知维修操作并优化建筑方法。目前监测结构应力和故障的黄金标准是分布式光纤传感器，它利用细光纤电缆的属性变化来测量应变等方面。然而，光纤传感器基本上是有线连接到结构中，需要部署工作，并提供一个入口点，削弱了结构的完整性。更重要的是，光纤传感器只能测量沿着纤维轴的应变，这意味着不能直接测量结构的三维形状变形。此外，在地基和周围土壤/岩石中安装光纤传感器既耗时又昂贵，限制了它们在高风险项目中的使用。这个雄心勃勃的项目旨在开发一种低成本、无线、可嵌入的传感技术，可以从结构、地基和周围地面的深处测量三维结构变形，小到可以加入混凝土混合物或注入岩石中。每个传感器不仅可以测量其位置的变化，还可以测量方向的变化，从而产生完整的六个自由度传感器。其关键是使用低频磁场，能够穿透岩石，土壤，混凝土和水，信号损失最小，这与目前基于高频无线电的无线技术相比具有显着优势，即使是几厘米的混凝土也无法穿透。这些厘米级的低成本传感器与混凝土浇筑混合在一起，立即形成一个自组织和愈合的通信网络。这些设备从构件（例如柱或梁）浇筑的时刻开始监测，提供特定结构构件整个寿命期间的信息，从混凝土固化过程到加载，再到监测裂缝和腐蚀。当结构元素彼此相邻放置时，网络将自动扩展以形成更大的合并通信系统。传感器可以测量它们在结构内的精确位置和方向，以及这些位置和方向如何随时间变化。利用多个这样的传感器，可以感测结构元件的实际形状以及其如何随着负载弯曲或扭曲。这是目前不可能实现的使用任何其他分布式传感技术，低频矢量场的一个关键优势，具有幅度和方向在3-D中嵌入传感器的结构内的问题之一是保持操作在结构的寿命，这可能是几十年。这些传感器使用相同的低频磁场来收集能量，这些能量要么从周围磁场（如电源线）中收集，要么直接注入结构的金属加固件中。这种技术有可能使建筑物和大型结构真正智能化，使用低成本，易于部署的传感器，可以从结构内部和周围的地基进行操作。这将能够实时监测结构生命周期内潜在故障的关键指标，为即将发生的灾难提供早期预警，并可能挽救生命。

项目成果

Reducing Magneto-Inductive Positioning Errors in a Metal-Rich Indoor Environment

减少富含金属的室内环境中的磁感应定位误差

• 发表时间: 2015
• 作者: Kypris O

Impact of Rocks and Minerals on Underground Magneto-Inductive Communication and Localization

• DOI: 10.1109/access.2016.2597641
• 发表时间: 2016-01-01
• 期刊: IEEE ACCESS
• 影响因子: 3.9
• 作者: Abrudan, Traian E.;Kypris, Orfeas;Markham, Andrew
• 通讯作者: Markham, Andrew

3-D Displacement Measurement for Structural Health Monitoring Using Low-Frequency Magnetic Fields

• DOI: 10.1109/jsen.2016.2636451
• 发表时间: 2017-02
• 期刊: IEEE Sensors Journal
• 影响因子: 4.3
• 作者: O. Kypris;A. Markham

In situ behavioral plasticity as compensation for weather variability: implications for future climate change

就地行为可塑性作为天气变化的补偿：对未来气候变化的影响

• DOI: 10.1007/s10584-018-2248-5
• 发表时间: 2018
• 期刊: Climatic Change
• 影响因子: 4.8
• 作者: Noonan M

Magnetic Induction-Based Positioning in Distorted Environments

扭曲环境中基于磁感应的定位

• DOI: 10.1109/tgrs.2016.2546461
• 发表时间: 2016
• 期刊: IEEE Transactions on Geoscience and Remote Sensing
• 影响因子: 8.2
• 作者: Kypris O