Premium
A powerful output‐feedback controller for uncertain nonlinear systems
Author(s) -
Man Yongchao,
Liu Yungang
Publication year - 2017
Publication title -
international journal of robust and nonlinear control
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.361
H-Index - 106
eISSN - 1099-1239
pISSN - 1049-8923
DOI - 10.1002/rnc.4014
Subject(s) - control theory (sociology) , controller (irrigation) , nonlinear system , control engineering , computer science , range (aeronautics) , adaptive control , state (computer science) , control (management) , engineering , artificial intelligence , physics , quantum mechanics , aerospace engineering , agronomy , biology , algorithm
Summary System nonlinearities, immeasurableness, and uncertainties (especially their coupling/coexistence) have constantly challenged the control design, which requires the controller to be powerful enough to counteract the resulting negative effects. In this paper, a global adaptive output‐feedback controller is designed for uncertain nonlinear systems. The proposed controller is of switching type, in which the design parameters are online adjusted on the basis of a switching logic in a recursive manner. This makes the controller powerful enough to compensate the system unknowns and dominate the system nonlinearities and therefore be applicable to a rather wide range of systems. Remarkably, our strategy allows the coexistence of an unknown control direction and unmeasured state–dependent growth but which are substantially excluded in the related literature. An example of the single‐link robot arm system is provided to illustrate the effectiveness of the proposed controller.