EFRI C3 SoRo: Design Principles for Soft Robots Based on Boundary Constrained Granular Swarms

这个项目将开发框架来理解建模、传感、控制、设计和制造一类新的软机器人。大多数软体机器人都避开了传统机器人的刚性环节，而采用柔性结构。相比之下，这项工作中设计的机器人的“柔软”来自于包裹在柔性膜中的颗粒材料之间的相互作用。这个概念最好通过考虑变形虫来实现，变形虫的外膜松散地封装了一组内部组件。通过允许膜外围的组件成为活动的“子机器人”，就像草履虫外围的纤毛一样，整个结构可以像一个边界受限的机器人群一样移动和变形。此外，为了操纵物体并对环境施加较大的力，机器人还将具有独特的堵塞能力。当粒子挤得太紧时，它们就会形成固体（就像真空袋中的咖啡渣），而不是相互流动（就像罐头里的咖啡渣）。这项工作的结果可能比传统机器人有几个优势，包括更好地适应物体的能力，与其他软结构（如动物组织）的物理交互能力，以及在非结构化环境中移动的能力。这可能会影响到几个国家的需求，包括提供本质上安全的机器人，这些机器人可以与人类一起工作或与人类一起工作，从而大大提高美国制造业的竞争力。这项研究还包括一项全面的扩大参与计划，重点是雇用代表性不足的少数民族作为研究生研究助理，并通过本科生研究经验项目向代表性不足的少数民族伸出援手。这与PI之前参与芝加哥科学与工业博物馆的社会外展相结合。这里开发的机器人将是第一个扩展颗粒软机器人概念的机器人，将颗粒本身想象成活动机器人。虽然类似于机器人群，但这种新型机器人的不同之处在于，该项目将是第一个研究子机器人的集合如何与环境进行物理交互的项目。为了实现这一目标，新的建模技术以及传感和驱动算法将被创造出来。建模将考虑用于模拟子机器人颗粒动力学的多体刚体动力学，用于模拟子机器人连接的大变形连续体力学，确保模型预测在物理上可行的约束，以及将所有元素结合在一起的拉格朗日力学。感知和驱动算法将利用边界群的涌现智能来感知外部环境，并在不进行集中规划的情况下，鲁棒地驱动不同的全局行为来响应这种分布式感知。该项目通过融合来自多个不同学科的概念和研究人员来增强基础设施。在工程中，这包括动力学和控制，材料和结构力学，材料工程和形式设计理论。在物理学中，它包括软凝聚态物质领域，特别是干扰相变和“活性物质”动力学的概念。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This project will develop the framework to understand the modeling, sensing, control, design, and fabrication of a new class of soft robots. Most soft robots eschew the rigid links of traditional robots in favor of compliant structures. In contrast, the robot designed in this work has its "softness" emerge from the interactions among granular material encased in a flexible membrane. The concept is best visualized by considering an amoeba, in which an outer membrane loosely encapsulates a set of internal components. By allowing components on the periphery of the membrane to be active "sub-robots," much like the cilia on the periphery of a paramecium, the overall structure can move and deform like a boundary-constrained robotic swarm. Moreover, to manipulate objects and exert large forces on the environment, the robot will also have the unique ability to jam. Jamming occurs when particles become packed so closely that instead of flowing past each other (like coffee grounds in a can) they form a solid (like coffee grounds in a vacuum-packed bag). The results of this work may offer several advantages over traditional robots, including the ability to better conform to objects, physically interact with other soft structures such as animal tissue, and locomote in unstructured environments. This could impact several national needs, including providing inherently safe robots that work with or alongside humans to greatly improve US manufacturing competitiveness. The research also includes a comprehensive broadening participation plan with an emphasis on hiring underrepresented minorities as graduate research assistants and outreach to underrepresented minorities through a Research Experiences for Undergraduates program. This is coupled with societal outreach that builds upon the PI's previous involvement with the Chicago Museum of Science and Industry.The robot developed here will be the first to expand upon the concept of granular soft robots by imagining the granules themselves as active robots. While similar to robotic swarms, this new class of robots differs significantly in that this project will be the first to examine how the aggregate of sub-robots physically interacts with its environment. To make this possible, novel modeling techniques will be created as well as sensing and actuation algorithms. Modeling will take into account both multi-body rigid dynamics for modeling the dynamics of sub-robot granules, large deformation continuum mechanics for modeling sub-robot connections, constraints to ensure the model predictions are physically viable, and Lagrangian mechanics to bring all the elements together. The sensing and actuation algorithms will exploit emergent intelligence of the boundary swarm to sense the external environment and robustly actuate distinct global behaviors in response to such distributed sensing without any centralized planning. The project enhances infrastructure through melding concepts and researchers from multiple disparate disciplines. In engineering, this includes dynamics and control, mechanics of materials and structures, materials engineering, and formal design theory. In physics, it encompasses areas of soft condensed matter, in particular the concepts of the jamming phase transition and the dynamics of "active matter."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.