Premium
Global Practical Tracking for Nonlinear Systems With More Unknowns via Adaptive Output‐Feedback
Author(s) -
Jin Shaoli,
Liu Yungang,
Li Fengzhong
Publication year - 2018
Publication title -
asian journal of control
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.769
H-Index - 53
eISSN - 1934-6093
pISSN - 1561-8625
DOI - 10.1002/asjc.1563
Subject(s) - backstepping , control theory (sociology) , nonlinear system , observer (physics) , bounded function , tracking error , controller (irrigation) , computer science , polynomial , signal (programming language) , adaptive control , tracking (education) , mathematics , control (management) , artificial intelligence , psychology , mathematical analysis , pedagogy , physics , quantum mechanics , agronomy , biology , programming language
This paper investigates the global practical tracking via adaptive output‐feedback for a class of uncertain nonlinear systems. Essentially different from the closely related literature, the system under investigation possesses unknown time‐varying control coefficients and a polynomial‐of‐output growth rate, and meanwhile, the system nonlinearities and the reference signal allow serious unknowns. For this, an adaptive observer is designed to reconstruct the system unmeasured states, where a new dynamic gain is introduced to compensate the serious unknowns in the system nonlinearities and the reference signal. Based on this and by backstepping technique, an adaptive output‐feedback controller is successfully designed, such that all the states of the closed‐loop system are bounded, and the tracking error will be prescribed sufficiently small after a finite time. A numerical simulation is provided to demonstrate the effectiveness of the proposed method.