Switching Position-Torque Control for Series Elastic Actuators with Disturbance Observer

Abstract

This paper proposes a novel switch control for the series elastic actuator (SEA). This switch control provides more robust position control along with better impulse dissipation performance. SEA is an actuator technology commonly used in robotic applications that require safe and precise interaction control. The SEA has built-in spring elements to inherently measure or estimate the transmitted force. It is often used for the application where the relevant action between motion and force is needed. The switching problem between position and torque control is one of the major issues, especially in situations where both position and torque information are critical, such as collisions. To deal with this problem, we discuss the conventional switching method and suggest a new method. Besides, this paper describes the criteria for comparing and analyzing them and presents a new approach that utilizes the concept of power to evaluate the performance of switching algorithms.