SitS NSF-UKRI: Rapid Deployment of Multi-Functional Modular Sensing Systems in the Soil

土壤是一种全球资源，支撑着我们大部分的城市基础设施，是地下水的管道，是世界上许多地质灾害的主导材料。了解土壤的原位状态(应力水平、硬度、强度、渗透性)对于制定关于人类应该如何与土壤沉积物相互作用的有效和高效的决策至关重要。目前的大多数土工测量仪器都是将探头垂直穿透到土壤的浅层(最多几百米)。通常，探头在一个非常局部的区域一次只记录一种类型的数据(例如，位移、水分含量或温度梯度)。因此，决策中使用的地面模型依赖于相对零散的数据点之间的内插，并分别考虑相关参数(机械、水力、热力)。具有集成传感系统(BRIS)的挖掘机器人建立在设计圆锥渗透测试改装和佐治亚理工学院(GT)最近开发的小型原型挖掘机器人的基础上。研究目标是：(I)设计、建造和部署挖掘机器人传感器传输系统；(Ii)在挖掘过程中感知机械和物理信号，并使用机器学习来适应挖掘过程和传感策略；(Iii)使用颗粒力学、摩擦学、大变形连续介质力学模型和特征选择算法来解释土壤信号。GT的研究小组与英国帝国理工学院(ICL)的研究小组将合作实现研究目标，并共同为一批研究生和博士后研究人员提供建议。BRIS将在土壤勘探和场地描述方面实现范式转变。BRIS的传感器模块和推进部分都将是可堆叠的，因此探测器可以用不同的模块组合或相同的模块构建，但配置不同。BRIS将采用最低限度的布线，因此该项目的发现将为无线、远程控制、多方向地下传感铺平道路。这些技术最终将使深层沉积物表征和外星探测成为可能。长期部署多传感探头可用于检测与局部探头刺激无关的土壤性质的变化，如采矿活动引起的pH值变化或反复干旱导致的孔压变化。PIS将利用GT和ICL机构组织，从代表性不足的少数群体中招收学生。她们将与警觉岩土材料网络和GT女工程师协会合作，以吸引女性学生。Lead-PI将参与推广将LGBTQ社区纳入工程的外联活动，并将促进对所有项目团队成员的安全空间培训。与获取未受干扰的样本相关的挑战意味着可以在现场测量这些属性的探测器非常有用。在GT最近的原型工作的启发下，该团队将开发一种新型的多传感器系统BRIS，其中将包括几项重大进展：(A)使用软机器人和微控制使探测器能够在地下的任何方向导航；(B)这些探测器能够利用蠕动在土壤中自动推进；(C)在这些半自动探测器中安装多个微型传感器；以及(D)在数据分析和土壤模型开发中利用机器学习算法。最近开发的实验技术将被用来改进和优化推进机制；这些技术包括新的纹理、生物启发的锚、土壤烧蚀机制和自润滑过程。将设计和评估创新的传感器系统，以优化测量集，特别关注应力、应力波速度和声发射。新的深度强化机器学习算法将被用来改进挖掘轨迹，并适应现场采取措施的频率。特征选择算法将得到增强，以处理用于解释应力、孔压、地球物理和声学信号的大数据集。该项目还将提供对自走式桥梁贯通过程中干沙和饱和水沙的物理和力学响应的基本了解。多尺度数值模型将首次破译挖掘力学，通过将包括蠕变边界条件、颗粒相互作用和揭示机器人/土壤界面流变学的多尺度摩擦学模型的离散元模型与将适用于在更大尺度上预测土壤行为的大变形有限元流体力学弹塑性模型相结合。该项目通过“土壤中的信号(SITS)”机会获奖，美国农业部国家粮食和农业研究所(USDA NIFA)和英国研究与创新(UKRI)研究理事会：1)自然环境研究理事会(NERC)，2)生物技术和生物科学研究理事会(BBSRC)，3)工程和物理科学研究理事会(EPSRC)，以及科学和技术设施理事会(STFC)。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Soil is a global resource that supports most of our urban infrastructure, acts as a conduit for groundwater and is the dominant material in many of the world's geohazards. Understanding the in-situ state of soil (stress level, stiffness, strength, permeability) is essential to inform effective and efficient decisions about how humans should interact with soil deposits. Most current geotechnical measuring instruments involve vertical penetration of a probe into the soil to a shallow depth (up to a few hundred meters). Usually, the probe records only one type of data at a time (e.g. a displacement, a moisture content or a thermal gradient), in a very localized area. Consequently, the ground models used in decision-making rely on interpolation between relatively sporadic data points and consider relevant parameters (mechanical, hydraulic, thermal) separately. The Burrowing Robot with Integrated Sensing System (BRISS) builds on insight gained in designing Cone Penetration Test modifications and the more recent development of small prototype burrowing robots at the Georgia Institute of Technology (GT). The research objectives are to: (i) design, build and deploy a burrowing robotized sensor delivery system; (ii) sense mechanical and physical signals during the burrowing process and use machine-learning to adapt the burrowing process and the sensing strategy; (iii) interpret soil signals using particulate mechanics, tribology, large deformation continuum mechanics models and feature selection algorithms. The research group at GT, in collaboration with the research group at Imperial College London (ICL) in the UK, will collaborate to achieve the research objectives and to co-advise a cohort of graduate students and post-doctoral researchers. The BRISS will achieve a paradigm shift in soil exploration and site characterization. Both the sensor modules and the propulsion sections of the BRISS will be stackable, so that probes can be built up with different combinations of modules or the same modules but in different configurations. The BRISS will be minimally wired, thus the project findings will pave the way towards wireless, remotely controlled, multi-directional subsurface sensing. Such technologies will ultimately enable deep sediment characterization and extra-terrestrial exploration. The long-term deployment of multi-sensing probes could be used to detect variations of soil properties that are independent from localized probe stimuli, such as pH change consequent to mining activities or pore pressure change consequent to repeated droughts. The PIs will use GT and ICL institutional organizations to recruit students from under-represented minorities. They will engage with the ALERT Geomaterials network and GT Society of Women Engineers to attract female students. The lead-PI will participate in outreach activities for promoting the inclusion of the LGBTQ community in engineering and will facilitate Safe Space training for all the project team members.Challenges associated with obtaining undisturbed samples mean that probes that can measure these properties in-situ are incredibly useful. Informed by recent prototyping work at GT, the team will develop a novel multi-sensor system, BRISS, which will incorporate several major advances: (a) the use of soft robot and micro-controls to enable probes to navigate in any orientation in the subsurface; (b) the ability of these probes to self-propel through the soil using peristaltic motion; (c) the incorporation of multiple micro-sensors in these semi-autonomous probes; and (d) the leveraging of machine learning algorithms into the data analysis and soil model development. Recently developed experimental techniques will be used to refine and optimize the propulsion mechanism; these include novel textures, bio-inspired anchors, soil ablation mechanisms and self-lubrication processes. Innovative sensor systems will be designed and evaluated to optimize the set of measurements, with a particular focus on stress, stress wave velocity and acoustic emissions. Novel deep reinforcement machine learning algorithms will be used to refine the burrowing trajectory and adapt the frequency at which in situ measures are taken. Feature selection algorithms will be enhanced to handle large data sets for interpreting stress, pore pressure, geophysical and acoustic signals. This project will also provide fundamental understanding of the physical and mechanical response of dry and water-saturated sand during the penetration of the self-propelled BRISS. For the first time, multi-scale numerical models will decipher burrowing mechanics, by combining discrete element models that will include peristaltic boundary conditions, particle interaction and multi-scale tribological models that will shed light on the robot/soil interface rheology, and large-deformation finite element hydro-mechanical elasto-plastic models that will be applicable to predict soil behavior at larger scales.This project was awarded through the "Signals in the Soil (SitS)" opportunity, a collaborative solicitation that involves the United States Department of Agriculture National Institute of Food and Agriculture (USDA NIFA) and the following United Kingdom Research and Innovation (UKRI) research councils: 1) The Natural Environment Research Council (NERC), 2) the Biotechnology and Biological Sciences Research Council (BBSRC), 3) the Engineering and Physical Sciences Research Council (EPSRC), and the Science and Technology Facilities Council (STFC).This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.