Magnetic Cogging Parallel-elastic Actuators for Energy-efficient Robotic Legs

该奖项探索了一种新的使能技术，用于灵活、高效、安全地与人类互动的下一代机器人：磁齿槽平行弹性致动器（MC-PEA）。MC-PEA特别有希望用于机器人腿，包括假肢、外骨骼和自主机器人（如人形和四足动物）的腿。MC-PEA包括一个与无源磁阻转矩元件（CTE）并联的电动机。MC-PEA的定义特征是它有一个离散的，由强被动磁弹簧创建的可控制的设计稳定平衡集。电机不需要能量来保持静态负载。相反，需要能量爆发才能使CTE转向邻近的平衡状态。MC-PEA将有效地实现受生物启发的运动原语，包括多种共振模式，这将导致行走和跑步期间所需的有效振荡运动。MC-PEA将成为普遍使用的串联弹性致动器（SEA）的节能替代品，目前SEA是应用的首选解决方案。此外，该奖项将支持研究生的培训和指导，将本科生纳入研究，以及改进教学课程。该授权的目的是表征磁齿槽平行弹性致动器（MC-PEA）的自然和强制动力学，并确定如何有效和高效地控制机器人运动。这项工作将提高对优化设计的MC-PEA跨越潜在参数变化的性能规格的理解。MC-PEA将通过在动力踝关节假体和有腿机器人中的应用来探索其优势。该方法包括研究受生物启发的动态运动基本要素——包括阻抗控制、点对点子运动和振荡——使用一个带有简单点状脚的双连杆机器人腿和MC-PEAs为臀部和膝盖提供动力。这项研究还包括开发定制的能量再生电路，这种电路可以快速打开和关闭，以便在动态运动中回收能量。项目成果将是各种步长下磁齿槽-扭矩元件（CTE）的最佳参数设计，并将分发给机器人设计师。该项目由跨部门机器人基础研究项目支持，由工程（ENG）和计算机与信息科学与工程（CISE）联合管理和资助。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 award explores a novel enabling technology for next-generation robots that are agile, efficient, and that safely interact with humans: the magnetic cogging parallel-elastic actuator (MC-PEA). The MC-PEA is particularly promising for use in robotic legs, including prostheses, exoskeletons, and the legs of autonomous robots such as humanoids and quadrupeds. The MC-PEA comprises an electric motor connected in parallel with a passive magnetic cogging-torque element (CTE). The defining characteristic of the MC-PEA is that it has a discrete, controllable-by-design set of stable equilibria created by strong passive magnetic springs. No energy is required from the motor to simply hold a static load. Rather, bursts of energy are required to cause the CTE to cog over to a neighboring equilibrium. The MC-PEA will efficiently implement bioinspired motion primitives, including multiple resonance modes that will lead to efficient oscillatory movements required during walking and running. The MC-PEA will represent an energy-efficient alternative to the ubiquitous series-elastic actuator (SEA) in applications in which the SEA is currently the go-to solution. In addition, this award will support training and mentorship of graduate students, inclusion of undergraduate students in research, and improvements to teaching curriculum.The objective of this grant is to characterize the natural and forced dynamics of the magnetic cogging parallel-elastic actuator (MC-PEA) and determine how to control it effectively and efficiently for robotic motions. The work will improve understanding of the performance specifications of an optimally designed MC-PEA across potential parameter variations. The benefits of the MC-PEA will be explored through application in powered ankle prosthesis and legged robots. The approach includes investigation of bioinspired dynamic motion primitives—including impedance control, point-to-point sub-movements, and oscillations—using a two-link robotic leg with a simple point-like foot and with MC-PEAs powering the hip and the knee. The research also includes development of custom energy regeneration circuits that can be rapidly switched on and off to enable energy to be reclaimed during dynamic movements. The project outcomes will be the optimal parametric designs of the magnetic cogging-torque element (CTE) for a wide variety of step sizes, to be disseminated to robot designers.This project is supported by the cross-directorate Foundational Research in Robotics program, jointly managed and funded by the Directorates for Engineering (ENG) and Computer and Information Science and Engineering (CISE).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.