Design of a Compliant Joint Based on Antagonistic-Driven Torsion Springs

This paper proposes a novel series elastic actuator (SEA) based on torsion springs with antagonistic structure intended for human-robot interaction. Different from the traditional compliant joints constructed with torsion spring, the proposed novel SEA utilizes two torsion spring modules to construct the antagonistic structure for alleviating the empty return journey. The expression that depicts the relationship between the design parameters and stiffness of torsion spring is derived, which is conducive to designing proper torsion spring for a desired stiffness. Finally, experiments are conducted to verify the effectiveness of the proposed SEA for a friendly human-robot interaction.