Robust tracking composite nonlinear feedback controller design for time-delay uncertain systems in the presence of input saturation

Valiollah Ghaffari; Saleh Mobayen; Sami Ud Din; Thaned Rojsiraphisal; Mai The Vu

doi:10.1016/j.isatra.2022.02.029

Robust tracking composite nonlinear feedback controller design for time-delay uncertain systems in the presence of input saturation

ISA Trans. 2022 Oct;129(Pt B):88-99. doi: 10.1016/j.isatra.2022.02.029. Epub 2022 Feb 24.

Authors

Valiollah Ghaffari¹, Saleh Mobayen², Sami Ud Din³, Thaned Rojsiraphisal⁴, Mai The Vu⁵

Affiliations

¹ Department of Electrical Engineering, Persian Gulf University, Bushehr, Iran.
² Department of Electrical Engineering, University of Zanjan, Zanjan, Iran; Future Technology Research Center, National Yunlin University of Science and Technology, 123 University Road, Section 3, Douliou, Yunlin 64002, Taiwan. Electronic address: mobayen@znu.ac.ir.
³ Department of Electrical Engineering, Namal University Mianwali, Mianwali 42250, Pakistan.
⁴ Advanced Research Center for Computational Simulation, Department of Mathematics, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand; Data Science Research Center, Department of Mathematics, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand. Electronic address: thaned.r@cmu.ac.th.
⁵ School of Intelligent Mechatronics Engineering, Sejong University, Seoul 05006, South Korea. Electronic address: maithevu90@sejong.ac.kr.

PMID: 35264305
DOI: 10.1016/j.isatra.2022.02.029

Abstract

In this study, a robust control technique is investigated for the reference tracking of uncertain time-delayed systems in the existence of the actuator saturation. Due to emerging of some control complexities, as well as the input limitations, time-varying delay, uncertainty, and external disturbance, such a tracking goal would be realized through suitable design of the composite nonlinear feedback (CNF) controller. Thus, considering the mentioned limitations, a Lyapunov-based procedure is used to determine the control law. Then, the parameters of the CNF input are derived by using the solution of a linear matrix inequality (LMI) problem. The planned tracking idea is numerically implemented in two uncertain control systems. Some performance characteristics (i.e., the tracking error, boundedness, and transient responses) are compared with similar ones. Accordingly, the simulations illustrate the efficiency of the suggested control procedure over the existing CNF approaches.

Keywords: Composite nonlinear feedback; Input saturation; Linear matrix inequality; Robust control; Time-delay system.