A Robot that Swims Through Granular Materials

Crover是第一个能够在散装谷物中移动的小型机器人设备。它打算使用机载传感器扫描储存在筒仓中的谷物，并建立一个完整的条件地图，以便及早发现导致谷物变质的虫害。该机器人（英国专利号2567898）的工作原理是利用旋转部件产生周围颗粒颗粒层的流动，与非颗粒系统不同，它产生“升力”，推动它通过颗粒介质的“流化”层（见视频- https://vimeo.com/crover）。Crover的行为很大程度上取决于局部压力和颗粒性质，因此在深度和不同颗粒介质类型下的有效运动仍然是一个挑战。展望未来，该公司希望使机器人能够在不同的颗粒环境中行驶，比如沙质海床。因此，克罗弗与爱丁堡大学的约翰·罗耶和艾丹·布朗合作，全面了解克罗弗与颗粒介质相互作用的基本物理原理，并利用这一点来设计下一代机器人。在这个项目中，你将专注于回答以下问题：Crover（或更通用的推进机制）与颗粒材料相互作用的基本物理原理是什么？这是如何根据诸如颗粒大小或形状、水分或间隙流体（例如泥浆）的存在而变化的？这将包括通过小型实验室“筒仓”（环境控制室中的谷物箱）系统地研究Crover或其他测试系统的运动，并通过计算机模拟和/或数学建模获得更深入的了解。该项目将包括在克罗弗有限公司进行为期3-6个月的工业实习，在此期间，你将完全沉浸在公司中。通过这个项目，你将掌握颗粒流变学和相关技术方面的专业知识，并将成为爱丁堡物理学院非常活跃的多学科软物质和生物物理研究所的一员。

The Crover is the first small robotic device able to move within bulk grains. It is intended to use on-board sensors to scan cereal grains stored in silos and build a full map of conditions for early detection of infestations leading to grain spoilage. The robot (UK Patent No.2567898) works by using rotating parts to generate flow of the surrounding layer of granular particles that, unlike what would happen in non-granular systems, results in 'lift' forces that propel it through the 'fluidised' layer of granular medium (see video - https://vimeo.com/crover). The behaviour of the Crover strongly depends on local pressure and granular particle properties, so that efficient motion at depth and in different granular media types remains a challenge. Looking further ahead, the company wants to enable the robot to navigate different granular environments, such as sandy seabeds. Crover have therefore teamed up with John Royer and Aidan Brown at Edinburgh University to fully understand the fundamental physics of the Crover's interaction with the granular medium, and to take advantage of this to design the next generation of robots.In this project you will focus on answering the question: What is the fundamental physics underlying the interaction of the Crover (or more generic propulsion mechanisms) with granular materials; how does this vary based on properties such as grain size or shape, the presence of moisture or of an interstitial fluid, e.g. in mud? This will involve systematically investigating the motion of the Crover or other test systems through small-scale lab 'silos' (a grain box in an environmentally controlled chamber), and gaining greater understanding through computer simulation and/or mathematical modelling. The project will involve an industrial placement at Crover Ltd. for 3-6 months, during which you will become fully immersed in the company. Through this project you will develop expertise in granular rheology and associated techniques, and will become part of the very active and multi-disciplinary Soft Matter and Biophysics research institute in Edinburgh Physics.