Finite-time disturbance observer-based trajectory tracking control for flexible-joint robots

• Published in: Nonlinear dynamics Vol. 106; no. 1; pp. 459 - 471
• Main Authors: Wang, Huiming, Zhang, Yang, Zhao, Zhenhua, Tang, Xianlun, Yang, Jun, Chen, I-Ming
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-09-2021; Springer Nature B.V
• Subjects: Aeronautics; Automation; Automotive Engineering; Classical Mechanics; Closed loop systems; Control; Controllers; Design; Disturbance observers; Dynamic models; Dynamical Systems; Engineering; Feedback control; Laboratories; Mechanical Engineering; Original Paper; Output feedback; Position measurement; Robot control; Robotics; Robots; Robust control; Stability analysis; Tracking control; Tracking problem; Trajectory control; Vibration; Finite-time disturbance observer (FTDO); Finite-time control; Flexible-joint robots (FJRs); Time-varying disturbance
• ISSN: 0924-090X; 1573-269X
• DOI: 10.1007/s11071-021-06868-4

This paper proposes a robust finite-time control scheme for the high-precision tracking problem of (FJRs) with various types of unpredictable disturbances. Specifically, based on a flatness dynamic model, a finite-time disturbance observer (FTDO) with only link-side position measurements is firstly developed to estimate the lumped unknown time-varying disturbance and unmeasurable states. Then, through the information of the states and disturbances provided by the FTDO, a robust output feedback controller is constructed, which can accomplish the tasks of disturbance suppression and trajectory tracking in finite time. Moreover, a rigorous stability analysis of the closed-loop system based on a finite-time bounded (FTB) function is conducted. Finally, the simulation results validate the feasibility and superiority of the proposed control scheme against other existing control results.