Development of Control System for a SEA-Joint Based on Active Damping Injection

Abstract

This paper is devoted to the choice and justification of a joint-level controller for a joint with intrinsic elasticity. Such joints show a number of advantages in terms of shock robustness, interaction safety, energy efficiency and so on. On the other hand, the addition of elastic element, i.e. a torsion spring, leads to oscillating behaviour. Thus, more elaborate controller structure is required. Active damping injection approach is chosen in this article to improve the joint performance and achieve smooth motion. A method to select controller gains is suggested as well which allows step-wise customization, by which either the settling time can be minimized or the motion can be made fully smooth. Finally, the controller performance is verified in simulation.