Observer-based fuzzy adaptive event-triggered control for strictly uncertain nonlinear systems with partial state constraints and output dead-zones

Abstract

This paper delves into the fuzzy adaptive event-triggered tracking control for a certain class of strictly uncertain nonlinear systems subject to partial state constraints as well as output dead-zones. First of all, fuzzy logic systems (FLSs) are utilised to approximate the unpredictable items, a fuzzy adaptive observer is intended to enable state estimation. Subsequently, a type of smooth approximate model is introduced to settle the nondifferentiable phenomenon of output dead-zones. To reduce the computational overhead of the communication operation effectively, an improved event-triggered control strategy including a decreasing hyperbolic tangent function related to dead-zone, is applied to determine the actual control input. In addition, the barrier Lyapunov function (BLF) is fabricated to address the issue of partial state constraint. By theoretical analysis, the reference signal can be precisely tracked by the system output and all closed-loop signals remain uniformly ultimately bounded (UUB). Finally, the constructed controller's effectiveness is validated with two illustrative examples.

Keywords:

• Adaptive control
• output dead-zone
• event-triggered control (ETC)
• fuzzy adaptive observer

Data availability statement

Date sharing is not applicable to this article as no new data were created or analysed in this study.

Disclosure statement

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

Additional information

Funding

The work was supported in part by the National Natural Science Foundation of China [grant numbers 62022044, 61773221, 61773072, 61873024 and U21A20483], the Jiangsu Natural Science Foundation for Distinguished Young Scholars [grant number BK20190039], the Natural Science Foundation of Liaoning Province [grant number 2022-MS-356], and the Scientific Research Foundation of Liaoning Educational Committee [grant numbers LJKZ0284 and 2020LNJC11].