On Gain Selection of Active Damping Injection Controller for Series Elastic Actuators

Abstract

Among different types of robotic actuators, series elastic actuators (SEA) have found their well-deserved place in last decades. With all the advantages of SEA they all possess one inherent drawback, which is the oscillatory behavior due to the presence of the elasticity. Thus, control system designers searched for answers to two questions: what structure should the controller have? and how to select the values of the controller gains? Certainly, the first question is more fundamental, but still the implementation is not convenient or even possible if the second question is neglected. A brief history on the types of SEA-control approaches as well as on the gain tuning for some of them is presented in the current article while the contribution of the article is the gain selection strategy for a recently suggested controller based on active damping injection.