Open AccessSimultaneous robust actuator and sensor fault estimation for uncertain non‐linear Lipschitz systems
Author(s) -
Zhang Jian,
Swain Akshya Kumar,
Nguang Sing Kiong
Publication year - 2014
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.2014.0096
Subject(s) - control theory (sociology) , actuator , lipschitz continuity , fault detection and isolation , fault (geology) , computer science , robustness (evolution) , linear system , control engineering , mathematics , engineering , control (management) , artificial intelligence , mathematical analysis , seismology , geology , biochemistry , chemistry , gene
The present study proposes two schemes for simultaneously estimating actuator and sensor faults for a class of uncertain non‐linear systems. In the first scheme, two sliding mode observers (SMOs) are designed to estimate actuator and sensor faults, respectively, under the assumption that the matching condition holds. In the second scheme, the assumption of matching condition is relaxed and an adaptive observer has been designed to estimate the sensor fault instead of using an SMO. The effects of the system uncertainties on the estimation errors of states and faults are reduced by integrating a prescribed ℋ ∞ disturbance attenuation level into the proposed schemes. The sufficient condition for the existence of the proposed observers with ℋ ∞ tracking performance is derived and expressed as a linear matrix inequality optimisation problem such that the ℒ 2 gain between the estimation errors and system uncertainties is minimised. Finally, a simulation study is presented to illustrate the effectiveness of the proposed schemes.