Continuous Terminal Sliding-Mode Control for FJR Subject to Matched/Mismatched Disturbances

• Published in: IEEE transactions on cybernetics Vol. 52; no. 10; pp. 10479 - 10489
• Main Authors: Wang, Huiming, Zhang, Qiyao, Sun, Zhenxing, Tang, Xianlun, Chen, I-Ming
• Format: Journal Article
• Language: English
• Published: United States IEEE 01.10.2022; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Aerodynamics; Control methods; Disturbances; Feedback control; Finite-time control (FTC); flexible-joint robots (FJR); mismatched disturbance; Robot control; Robots; Robust control; Sliding mode control; sliding-mode control (SMC); Stability analysis; Telecommunications; Trajectory tracking; Uncertainty
• ISSN: 2168-2267; 2168-2275; 2168-2275
• DOI: 10.1109/TCYB.2021.3066593

A robust finite-time control (FTC) framework using continuous terminal sliding-mode control (SMC) and high-order sliding-mode observer (HOSMO) is discussed to realize the trajectory tracking of flexible-joint robots in this article. Control performances of the robots always suffer from unknown matched and mismatched time-varying disturbances. Traditional SMC exists with a chattering phenomenon and cannot cope with mismatched time-varying disturbances due to its inherent structure property. For this reason, two HOSMOs are devised to estimate the time-varying disturbances on the link and motor side, respectively. Then, by fusing the states and disturbance estimations into a novel terminal sliding-mode surface, a continuous robust FTC scheme is developed. The proposed control strategy can not only handle both matched and mismatched time-varying disturbances but also obtain a finite-time convergence performance. The rigorous finite-time stability analysis of the closed-loop system under the proposed control method is guaranteed. The results are illustrated to verify the effectiveness and robustness of the proposed design approach.