A Rolling Flexure Mechanism for Progressive Stiffness Actuators.

Linear Series Elastic Actuators exhibit a restricted design space. This inevitably leads to design trade-offs translating into robot performance limitations. These prevent robots from eventually reaching human comparable soft but also powerful physical interaction performance.This work presents a novel fixed passive rolling flexure design principle enabling the realization of a wide range of progressive torque-deflection characteristics. The proposed principle displays low hysteresis and can be manufactured in single 2D components. The paper derives the analytic foundation for the rolling flexure principle and is supported by numerical finite element analysis. The theory is validated by experimental results obtained on two laboratory prototypes.