Design and Modelling of a Compact Variable Stiffness Mechanism for Wearable Elbow Exoskeletons

This paper presents a compact variable stiffness mechanism (VSM) with reconfigurability. The VSM is able to achieve variable stiffness in adjustable ranges, due to its reconfigurable design. The new VSM features with a compact and light weight structure, and can be used as a stand alone module, or integrated in wearable elbow exoskeletons and other transmissions. In the paper, mechanics models are developed for VSM to reveal the stiffness performance and torque-deflection characteristics. A prototype of VSM is constructed and static testing results validate the models. The proposed VSM is finally integrated in a wearable elbow exoskeleton.