ABSTRACT
This paper deals with asymptotic stabilisation of a class of nonlinear input-delayed systems via dynamic output feedback in the presence of disturbances. The proposed strategy has the structure of an observer-based control law, in which the observer estimates and predicts both the plant state and the external disturbance. A nominal delay value is assumed to be known and stability conditions in terms of linear matrix inequalities are derived for fast-varying delay uncertainties. Asymptotic stability is achieved if the disturbance or the time delay is constant. The controller design problem is also addressed and a numerical example with an unstable system is provided to illustrate the usefulness of the proposed strategy.
Disclosure statement
No potential conflict of interest was reported by the authors.
ORCID
R. Sanz http://orcid.org/0000-0001-8581-2742
P. García http://orcid.org/0000-0002-1202-1269
E. Fridman http://orcid.org/0000-0002-8773-9494
P. Albertos http://orcid.org/0000-0002-7277-5927
Notes
1 The equality was used to derive (Equation12(12) (12) ), which can be obtained by subtracting and as defined in (Equation10(10) (10) ), delaying the resulting expression by h/m units of time, and using the fact that .