Flocks of Swimming Micro-robots with Long-range Hydrodynamic Interaction and Objectives

该项目将创造一群游泳机器人，这些机器人在高粘性流体环境中运行并相互影响。由于尺寸对不同流体力的相对贡献的影响，水中的微米级机器人的行为与玉米糖浆或机油等粘性流体中的厘米级机器人相似。高粘性流体也可以模拟颗粒介质（如沙子）中的运动。高粘度的一个影响是，一个机器人的运动可能会影响许多身体长度远的其他机器人。因此，该项目将为考虑这些相互作用的大型游泳机器人群创建轨迹规划和运动控制的新方法。两种可选的控制模式将是本研究的重点。第一个是最大限度地扩大游泳群体的长期影响，以加强流体环境的混合。第二个是尽量减少远程影响，以便允许机器人群的隐形移动。这些群的一些潜在应用包括油罐的机器人检查，环境监测和修复，以及血管中的多药剂药物输送系统。该项目是多学科的，涵盖从基础流体力学到机器人设计和控制。与这一多学科提案相关的研究和教育活动预计将使该主题面向广泛的受众，包括传统上代表性不足的群体和与国家工业相关的工程界。创造能够在高粘性环境中移动和翻滚的人工游泳者带来了许多根本性的挑战。在粘性制度游泳显着影响的远程水动力相互作用，非线性耦合的推进功能的游泳者在一个群体。长距离流体动力学相互作用很容易诱发混沌，导致不可预测的集体行为。这个项目解决了第一个三维控制下的非线性水动力相互作用的游泳群体。作为一个基准，实验将进行使用一个游泳者称为Quadroar，和这个游泳者之间切换（准）周期性和混乱的群体行为的能力将进行调查。两个基本的任务将被实施：（i）一个群体的主动最佳控制，以实现最高的混合效率在背景流体（混沌混合模式）;和（ii）一个群体的主动控制，使流体动力学相互作用相互抵消，也就是说，游泳者群体与周围的流体干扰最小，并保持隐形（隐藏群模式）。这些模式定义了新的环境介导的机器人群体的群体目标。

This project will create flocks of swimming robots that operate in, and cooperatively influence, highly viscous fluid environments. Because of the effect of size on the relative contributions of different fluid forces, micrometer-scale robots in water behave similarly to centimeter-scale robots in viscous fluids such as corn syrup or motor oil. High viscous fluids can also model movement in granular media like sand. One effect of high viscosity is that the movement of one robot may affect other robots many body lengths distant. Thus this project will create new methods of trajectory planning and motion control for large flocks of swimming robots that take these interactions into account. Two selectable modes of control will be the focus of this study. The first is to maximize the long-range effects of the swimming flock, so as to enhance mixing of the fluid environment. The second is to minimize long-range effects, so as to allow stealthy movement of the robot flock. Some potential applications of these flocks include robotic inspection of oil tanks, environmental monitoring and remediation, and multi-agent drug delivery systems in blood vessels. This project is multidisciplinary covering from fundamental fluid mechanics to robot design and control. The research and educational activities associated with this multidisciplinary proposal are expected to make the subject accessible to a broad audience including traditionally under-represented groups and engineering community affiliated with national industries.The creation of artificial swimmers capable of moving and tumbling in highly viscous environments poses numerous fundamental challenges. Swimming in viscous regimes is significantly affected by long-range hydrodynamic interactions that nonlinearly couple the propulsion function of swimmers in a swarm. Long-range hydrodynamic interactions can easily induce chaos, and lead to unpredictable collective behaviors. This project addresses the first three-dimensional controlled flock of swimmers under nonlinear hydrodynamic interactions. As a benchmark, experiments will be conducted using a swimmer called Quadroar, and the capability of this swimmer to switch between (quasi) periodic and chaotic group behaviors will be investigated. Two fundamental missions will be implemented: (i) Active optimal control of a flock to achieve the highest mixing efficiency in the background fluid (Chaotic Mixing mode); and (ii) Active control of a flock such that hydrodynamic interactions cancel each other, that is, swimmers flock with minimally disturbing the surrounding fluid, and remain stealth (Concealed Swarm mode). These modes define new group objectives for environment-mediated robotic swarms.