Lee, Yisoo Tsagarakis, Nikos Ott, Christian Lee, Jinoh 2024-01-12T03:31:55Z 2024-01-12T03:31:55Z 2022-02-25 2022-04 2377-3766 https://pubs.kist.re.kr/handle/201004/76766 Actuation failure and fault-tolerant control under the actuation failure scenario have drawnmore attention in accordance with the recent increasing demand for reliable robot control applications such for long-term and remote operation. The emergence of control torque loss, i.e., the free-swinging failure, is particularly challenging when the robot performs dynamic operational space tasks due to complexities stemming from redundancies in the kinematic structure as well as a dynamical disturbance in the under-actuated multi-body system. To reinforce robustness and accuracy of task-space control under the failure condition, this letter proposes a performance index, named generalized failure-susceptibility (GFS), which is formulated to render thorough dynamic and kinematic effects caused by the un-actuated joints. The GFS index is then exploited with the hierarchical task controller, where self-motion is controlled to minimize the index in real-time. Several experiments with a seven-degrees-of-freedom torque-controlled robot verify that the proposed control strategy with the GFS index effectively improves fault tolerance against anticipating actuation failure. English Institute of Electrical and Electronics Engineers Inc. A Generalized Index for Fault-Tolerant Control in Operational Space Under Free-Swinging Actuation Failure Article 10.1109/LRA.2022.3140425 1 IEEE Robotics and Automation Letters, v.7, no.2, pp.1486 - 1493 IEEE Robotics and Automation Letters 7 2 1486 1493 N scie scopus 000742180000027 2-s2.0-85122573269 Robotics Robotics Article FRAMEWORK MOTION TORQUE FORCE KINEMATICALLY REDUNDANT MANIPULATORS ROBOT Failure detection and recovery redundant Robots underactuated robots