Robust adaptive fuzzy control for non-strict feedback switched nonlinear systems with unmodeled dynamics

Abstract

In this paper, a novel fuzzy adaptive output-feedback control design scheme is concerned for a class of non-strict feedback switched nonlinear systems. The considered nonlinear system contains arbitrary switching, unmodeled dynamics, unmeasured states, and unknown nonlinearities. In the design process, fuzzy logic systems (FLSs) are utilised to identify the unknown nonlinear functions. A state observer without depending on the switching signal is constructed to deal with the unmeasured states. By combining adaptive backstepping with dynamic surface control (DSC) technique, a fuzzy adaptive control scheme is presented to overcomes the ‘explosion of complexity’ problem. It is proved that all the signals of the closed-loop system can be bounded by the common Lyapunov function theory. Finally, a simulation example is provided to elaborate the feasibility and effectiveness of the proposed control method.

Keywords:

• Unmodeled dynamics
• output-feedback control
• non-strict feedback
• switched nonlinear systems
• fuzzy adaptive control

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [grant number 61773188], [grant number 61822307].

Notes on contributors

Wei Wu

Wei Wu received the B.S. degree in information and computing science from the Liaoning University of Technology, Jinzhou, China, in 2017, where he is currently pursuing the M.E. degree in applied mathematics.

His current research interests include switched control, fuzzy control, and adaptive control.

Shaocheng Tong

Shaocheng Tong (SM’15) received the B.S. degree in Mathematics from Jinzhou Normal College, Jinzhou, China, the M.S. degree in Fuzzy Mathematics from Dalian Marine University, Dalian, China, and the Ph.D. degree in Fuzzy Control from the Northeastern University, Shenyang, China, in 1982, 1988, and 1997, respectively.

He is currently a Professor with the College of Science, Liaoning University of Technology, Jinzhou, China. His current research interests include fuzzy and neural networks control, and nonlinear adaptive control.