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

该奖项探索了一种新的使能技术，用于下一代机器人，这些机器人敏捷，高效，并与人类安全地互动：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的腿，如类人和四足动物。MC-PEA包括与被动磁性齿槽转矩元件（CTE）并联连接的电动机。MC-PEA的定义特征是它具有由强被动磁性弹簧创建的离散的、可通过设计实现的稳定平衡集。电机不需要能量来简单地保持静态负载。相反，需要能量的爆发来使CTE转向邻近的平衡。MC-PEA将有效地实现生物启发的运动基元，包括多个共振模式，这将导致步行和跑步期间所需的有效振荡运动。MC-PEA将代表无处不在的串联弹性致动器（SEA）的节能替代方案，在这些应用中，SEA是目前的首选解决方案。此外，该奖项还将支持研究生的培训和指导，将本科生纳入研究，并改进教学课程。该赠款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，并确定如何有效地控制它，以实现机器人运动。这项工作将提高对优化设计的MC-PEA在潜在参数变化中的性能规格的理解。MC-PEA的好处将通过在动力踝关节假体和腿式机器人中的应用来探索。该方法包括生物启发的动态运动连续性的调查，包括阻抗控制，点到点的子运动，和振荡，使用一个简单的点样脚和MC-PEAs动力髋关节和膝关节的双连杆机器人腿。该研究还包括开发定制的能量再生电路，可以快速打开和关闭，使能量在动态运动中回收。该项目的成果将是磁齿槽扭矩元件（CTE）的各种步长的最佳参数设计，将分发给机器人设计师。该项目得到了跨部门机器人基础研究计划的支持，由工程局（ENG）和计算机与信息科学与工程局（CISE）共同管理和资助该奖项反映了NSF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.