A Comparative Study on 2-DOF Variable Stiffness Mechanisms

Christoph Stoeffler; Shivesh Kumar; Andreas Müller

In: Jadran Lenarčič; Bruno Siciliano (Hrsg.). Advances in Robot Kinematics 2020. Pages 259-267, ISBN 978-3-030-50975-0, Springer, 7/2020.


Based on the idea of variable stiffness mechanisms, a variety of such mechanisms is shown in this work. Specifically, 2-DOF parallel kinematic machines equipped with redundant actuators and non-linear springs in the actuated joints are presented and a comparative overview is drawn. Accordingly, a general stiffness formulation in task space of all mechanisms is given. Under fixed geometric parameters, optimization of task space stiffness is carried out on the designs comprising all kinematic solutions. Finally, a stiffness metric is introduced that allows a quantitative comparison of the given mechanism designs. This gives rise to design guidelines for engineers but also shows an interesting outline for future applications of variable stiffness mechanisms.

Deutsches Forschungszentrum für Künstliche Intelligenz
German Research Center for Artificial Intelligence