Open AccessRobust state estimation for non‐linear systems with unknown delays
Author(s) -
Nguyen Cuong M.,
Pathirana Pubudu N.,
Trinh Hieu
Publication year - 2019
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.2018.6248
Subject(s) - control theory (sociology) , observer (physics) , lipschitz continuity , computer science , linear system , inverted pendulum , state (computer science) , differentiable function , robustness (evolution) , mathematics , state observer , nonlinear system , control (management) , algorithm , artificial intelligence , mathematical analysis , biochemistry , chemistry , physics , quantum mechanics , gene
In this study, the authors consider the state estimation problem for a class of non‐linear systems with unknown time‐varying delays. Based on theH ∞filtering method, they propose a new observer design approach where the states of the non‐linear systems with unknown delays can be robustly estimated. While relevant results in the literature assume the unknown delays to be differentiable, the observer design proposed in this study only requires the knowledge of the unknown delays' upper and lower bounds which can be obtained in practical systems. The new observer design approach also allows us to consider delays in the output measurements. They further utilise the linear parameter varying approach to relax the conservativeness imposed on observer design conditions by the Lipschitz conditions. To show the effectiveness of the new results, the single‐link joint robotic system and the pendulum system are considered as illustrative examples.