Backstepping control for a two-link manipulator with appointed-time convergence

Liang Zhang; Jiafu Liu; Naigang Cui

doi:10.1016/j.isatra.2021.10.005

Backstepping control for a two-link manipulator with appointed-time convergence

ISA Trans. 2022 Sep;128(Pt A):208-219. doi: 10.1016/j.isatra.2021.10.005. Epub 2021 Oct 12.

Authors

Liang Zhang¹, Jiafu Liu², Naigang Cui³

Affiliations

¹ School of Aeronautics and Astronautics, Sun Yat-sen University, Guangzhou, 510275, China.
² School of Aeronautics and Astronautics, Sun Yat-sen University, Guangzhou, 510275, China. Electronic address: liujf53@mail.sysu.edu.cn.
³ School of Astronautics, Harbin Institute of Technology, Harbin 150001, China.

PMID: 34702548
DOI: 10.1016/j.isatra.2021.10.005

Abstract

In this paper, a novel backstepping control law is investigated, which guarantees appointed-time convergence for a two-link manipulator. In contrast to other fixed-time controllers or predefined-time controllers, the practical convergence time can be precisely obtained instead of being estimated. By utilizing a novel appointed-time prescribed performance function, the trajectory tracking error of the manipulator can be previously constrained. Furthermore, the external disturbances have been suppressed by introducing a disturbance observer with the convergence time as a prior control parameter and a switching sliding mode control law. The stability of the controller is analyzed by the Lyapunov method. Various numerical simulation results are carried out to demonstrate the efficacy of the proposed control scheme.

Keywords: Appointed-time convergence; Backstepping control; Prescribed performance function; Two-link manipulator.