Nonlinear stiffness SEAs (NSEAs) inspired by biological muscles offer promise in achieving adaptable stiffness for assistive robots. While assistive robots are often designed and compared based on torque capability and control bandwidth, NSEAs have not been systematically designed in the frequency domain due to their nonlinearity. The describing function, an analytical concept for nonlinear systems, offers a means to understand their behavior in the frequency domain. This paper introduces a frequency domain analysis of nonlinear series elastic actuators using the describing function method. This framework aims to equip researchers and engineers with tools for improved design and control in assistive robotics.

翻译：生物肌肉启发的非线性刚度串联弹性作动器（NSEAs）有望在辅助机器人中实现可适应刚度。尽管辅助机器人的设计和比较常基于转矩能力与控制带宽，但由于其非线性特性，NSEAs尚未在频域中进行系统性设计。描述函数作为非线性系统的分析概念，为理解其在频域中的行为提供了方法。本文提出了一种采用描述函数法的非线性串联弹性作动器频域分析框架，旨在为研究者和工程师提供改善辅助机器人设计与控制的工具。