이중 탄성영역을 가지는 직렬 선형 탄성 구동기의 스프링 설계

Abstract

Series Elastic Actuator(SEAs) are widely used for precise torque control. The driving range of the SEA is determined by the spring and the encoder. Unfortunately, the elastic area of the spring is not infinite, and the resolution of the encoder is not infinitely small. Therefore, when the driving area exceeds the spring limit, the control performance deteriorates. For the above reasons, single spring SEAs, the trade-off between the precision of torque control and the stiffness of the spring puts a limit on the choice of the springs with more significant stiffness for applying a more significant assistive torque. In particular, this problem is remarkable in the cable-driven method, which is always driven by maintaining small tension to prevent cable disconnection. To resolve this issue, we designed a Dual-stage Series Reaction Force Elastic Actuator (DRFSEA) that acts as a SEA with better precision and a more significant appliable torque by actuating the operating range of the springs into two segments.