Open AccessChattering‐free robust finite‐time output feedback control scheme for a class of uncertain non‐linear systems
Author(s) -
Razmjooei Hamid,
Shafiei Mohammad Hossein,
Palli Gianluca,
Ibeas Asier
Publication year - 2020
Publication title -
iet control theory and applications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.059
H-Index - 108
eISSN - 1751-8652
pISSN - 1751-8644
DOI - 10.1049/iet-cta.2020.0910
Subject(s) - control theory (sociology) , observer (physics) , bounded function , state observer , linear system , integrator , mathematics , uniform boundedness , upper and lower bounds , controller (irrigation) , neighbourhood (mathematics) , computer science , nonlinear system , control (management) , bandwidth (computing) , mathematical analysis , computer network , physics , quantum mechanics , artificial intelligence , agronomy , biology
In this study, an innovative technique to design an observer‐based finite‐time output feedback controller (FT‐OFC) is proposed for a class of non‐linear systems. This controller aims to make the state variables converge to a small bound around the origin in a finite time. The main innovation of this study is to transform the non‐linear system into a new time‐varying form to achieve the finite‐time boundedness criteria using the asymptotic stability methods. Moreover, without any prior knowledge of the upper bounds of the system uncertainties and/or disturbances, and only based on the output measurements, a novel time‐varying extended state observer is designed to estimate the states of the non‐linear system as well as the uncertainties and disturbances in a finite time. In this way, the time‐varying gains of the extended state observer are designed to converge the observation error to a neighbourhood of zero while remaining uniformly bounded in finite time. Subsequently, an observer‐based time‐varying control law is designed to make the system globally uniformly bounded in finite time. Finally, the efficiency of the proposed FT‐OFC for a disturbed double integrator system with unknown measurement noise is illustrated by numerical simulations.