An Improved Mechanism for Rotational Variable Stiffness

This paper presents a variable-stiffness mechanism that uses the variable-lever principle to achieve a large range of output stiffness variation. It is unique in its use of a gear/rack pair to function both as a lever with a variable pivot point and as part of the stiffness-adjustment transmission mechanism. It improves on a previous design by reconfiguring some of the kinematic constraints on the gear, resulting in very efficient operation. Simulation experiments are presented to validate the design.