First Steps: The Dynamics and Control of Underwater Walking

第一步：水下行走的动力学和控制

• 批准号: 1929900
• 负责人: Henry Astley
• 金额: $ 29.73万
• 依托单位: University of Akron
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-01 至 2023-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1929900&HistoricalAwards=false
• 关键词: First; Steps; Dynamics; Control; Underwater

The colonization of land by animals is one of the greatest evolutionary events in the history of life, but our understanding of the physics of this occurrence is limited. Long before animals walked on land, the first steps were taken beneath the water's surface by animals walking on submerged substrates. This behavior formed the basis for eventual movement on land, but the physics display a complex mix of fluid forces (drag, buoyancy) and typical walking forces (foot-substrate interactions, gravity). Understanding of this behavior is limited by the inability to effectively measure the forces exerted on the substrate. This project will create a custom-designed force sensing system to record the small substrate forces that occur during underwater walking, and, combined with measurements of drag, buoyancy, and other fluid forces, will provide the first complete picture of the mechanics of this behavior. This will provide crucial insights into the evolution of walking and how animals adapted to the eventual transition onto land. In addition to providing valuable training for graduate students, this project will provide the scientific community with a new tool for investigating underwater forces and provide insights for the design of biologically-inspired underwater exploration vehicles.Effective locomotion was crucial to the initial invasion of land, and underwater walking was the key behavioral predecessor that was exapted into terrestrial use during this transition. However, the biomechanics and control of underwater walking are poorly known, in part due to the difficulty of measuring small substrate reaction forces. The combination of both fluid and substrate forces could make typical walking dynamics untenable, particularly the reduced effective body weight due to buoyant support, and damping effects from the surrounding fluid (particularly drag and the added mass effect). This project will investigate the dynamics and control of underwater walking via direct measurement of substrate reaction forces using a novel underwater force sensing system, combined with measurements of fluid forces, across variable substrates and environmental conditions. This will provide insights into how these forces interact and how animals control these interactions to produce controlled locomotion, as well as how changes in environment could affect these dynamics and how underwater walking could be exapted to a terrestrial setting. Effective understanding of these dynamics could provide insight into the use of underwater walking in extant species, the biomechanics of the ancient transitions from underwater to terrestrial walking, and insight into the control of underwater walking robotic systems for exploration.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.

动物对土地的殖民化是生命史上最伟大的进化事件之一，但是我们对这种情况的物理学的理解是有限的。 在动物在陆地上行走之前很久，第一步就通过在淹没的底物上行走的动物在水面下方。 这种行为构成了最终在陆地上运动的基础，但是物理学表现出复杂的流体力（拖动，浮力）和典型的步行力（脚部底物相互作用，重力）的混合。 理解这种行为是由于无法有效测量施加在底物上的力而受到限制。该项目将创建一个定制设计的力传感系统，以记录水下步行期间发生的小基材力，并结合拖动，浮力和其他流体力的测量，将提供这种行为机制的第一个完整图片。 这将提供有关步行演变以及动物如何适应最终过渡到土地的关键见解。 除了为研究生提供有价值的培训外，该项目还将为科学界提供一种新的工具来调查水下力量，并为设计生物学启发的水下勘探工具设计提供见解。有效的运动对于最初的陆地入侵至关重要，而水下步行是在陆上的关键行为，这是在这种跨越过程中的关键行为。 但是，水下步行的生物力学和控制是鲜为人知的，部分原因是难以测量较小的底物反作用力。 流体和底物力的结合可能会使典型的步行动力学难以忍受，尤其是由于浮力支撑而导致的有效体重减轻，以及周围流体的阻尼效应（尤其是阻力和附加的质量效应）。该项目将使用新型的水下力传感系统直接测量底物反作用力来研究水下行走的动力和控制，并结合了可变基板和环境条件的流体力的测量。这将提供有关这些力如何相互作用以及动物如何控制这些相互作用以产生受控运动的见解，以及环境的变化如何影响这些动态以及如何将水下行走置于陆地环境中。 对这些动力学的有效理解可以提供有关在现有物种中使用水下行走的洞察力，从水下到陆地步行的古代过渡的生物力学，以及深入了解水下步行机器人系统进行探索的控制。该奖项反映了NSF的立法任务，并被认为是通过基金会的智力评估来评估的，并值得通过评估来评估基金会的优点和广泛的范围。