ABSTRACT
This paper studies the problem of global output feedback control for nonlinear time-delay systems with input matching uncertainty and the unknown output function, whose nonlinearities are bounded by lower triangular linear unmeasured states multiplying the unknown constant, polynomial-of-output and polynomial-of-input growth rates. By constructing a new extended state observer and skillfully combining the dynamic gain method, backstepping method and Lyapunov–Krasovskii theorem, a delay-independent output feedback controller can be developed with only one dynamic gain. It is proved that all the signals of the closed-loop system are bounded, the states of the original system and the corresponding observer converge to zero, and the estimation of input matching uncertainty converges to its actual value. Two examples demonstrate the effectiveness of the control scheme.
Disclosure statement
No potential conflict of interest was reported by the authors.
ORCID
Jun Xia http://orcid.org/0000-0002-1224-6142
Yujia Zhang http://orcid.org/0000-0003-3991-7388
Chenguang Yang http://orcid.org/0000-0001-5255-5559
Min Wang http://orcid.org/0000-0001-7025-7651
Additional information
Funding
Notes on contributors
Chao Guo
Chao Guo is a doctoral student at the Institute of Automation, Qufu Normal University. Her current research interests include nonlinear control and adaptive control.
Xue-Jun Xie
Xue-Jun Xie is a professor at the Institute of Automation, Qufu Normal University. His current research interests include stochastic nonlinear control systems and adaptive control.