ADEA — Active Variable Stiffness Differential Elastic Actuator : Design and application for safe robotics

This paper presents an Active Variable Stiffness Differential Elastic Actuator (ADEA) which is designed and application for robotic systems and more generally for machines that are designed to interact with people and environments under safety constraints. The ADEA consists of two DC-motors to drive two antagonistic warm gears independently. By changing the synchronisation and differentiation of angle displacement of these two antagonistic warm gears, ADEA has the capacity to minimize large impact forces due to shocks, to safely interact with the user or become as stiff as possible to make precise position movements. Besides, the ADEA can achieve fast motion control while guaranteeing safety of human operators in worst-case impact situation because of the stiffness of ADEA is variable dynamically. Experimental results are presented to show performance and safety of a one-link arm actuated by the ADEA.