This paper develops an accurate force control algorithm for series elastic actuators (SEAs) based on a novel force estimation scheme, called transmission force observer (TFOB). The proposed method is designed to improve an inferior force measurement of the SEA caused by nonlinearities of the elastic transmission and measurement noise and error of its deformation sensor. This paper first analyzes the limitation of the conventional methods for the SEA transmission force sensing and then investigates its stochastic characteristics, which indeed provide the base to render the accurate force control performance incorporated with the TFOB. In particular, a tuning parameter is introduced from holistic closed-loop system analyses in the frequency domain. This gives a guideline to attain optimum performance of the force-controlled SEA system. The proposed algorithm is experimentally verified in an actual SEA hardware setup.
Safe rendering of high impedance on a series-elastic actuator with disturbance observer-based torque control
Fraunhofer Institute for Production Systems and Design Technology (IPK)（弗劳恩霍夫生产系统与设计技术研究所（IPK））；Daegu Gyeongbuk Institute of Science and Technology（大邱庆北科学技术院）
Learning to Control Emulated Muscles in Real Robots: Towards Exploiting Bio-Inspired Actuator Morphology
Max Planck Institute for Intelligent Systems（马克斯·普朗克智能系统研究所）；Hertie Institute for Clinical Brain Research（赫特希临床脑研究所在）；Centre for Integrative Neuroscience（整合神经科学中心）；University of Tübingen（图宾根大学）；Distributed Intelligence（分布式智能）；Institute of Computer Engineering (ZITI)（计算机工程研究所）
Data-driven Force Observer for Human-Robot Interaction with Series Elastic Actuators using Gaussian Processes
Technical University of Munich（慕尼黑工业大学）；TUM School of Computation, Information and Technology（慕尼黑工业大学计算、信息与技术学院）；BioRobotics Institute, Scuola Superiore Sant’Anna（圣安娜高等学校生物机器人研究所）；ETH Zurich（苏黎世联邦理工学院）
Design and Control of a Compact Series Elastic Actuator Module for Robots in MRI Scanners
Department of Electrical Engineering and Computer Sciences, University of California, Berkeley（电气工程与计算机科学系，加州大学伯克利分校）；Department of Mechanical, Aerospace, and Industrial Engineering, The University of Texas at San Antonio（机械、航空航天与工业工程系，德克萨斯大学圣安东尼奥分校）；Department of Mechanical Engineering, University of California, Berkeley（机械工程系，加州大学伯克利分校）
BSA -- Bi-Stiffness Actuation for optimally exploiting intrinsic compliance and inertial coupling effects in elastic joint robots
Munich Institute of Robotics and Machine Intelligence (MIRMI), Technical University of Munich（慕尼黑工业大学慕尼黑机器人与机器智能研究院（MIRMI））；Omar Al-Mukhtar University (OMU)（奥马尔·穆赫塔尔大学（OMU））
