|An Uncertainty-based Approach to Discrete-time Fault Estimation Observer design for nonuniformly sampled systems
Aibing Qiu*, Jing Zhang, and Juping Gu
International Journal of Control, Automation, and Systems, vol. 15, no. 4, pp.1651-1660, 2017
Abstract : "This paper considers the fault estimation problem of nonuniformly sampled system in which sensor
sampling is performed at aperiodic interval. After being discretized at sampling instant, the nonuniformly sampled
system is modeled as an equivalent polytopic system with norm bounded uncertainties. A discrete-time time-varying
fault estimation observer with multiple design freedom is then constructed, and a sufficient condition given in linear
matrix inequality (LMI) is provided to obtain the constant filter gain and ensure not only the asymptotic stability of
fault estimation error but also the robustness of uncertainties. Compared with the existing observer designed based
on continuous-time delay approach, the proposed one has a better estimation accuracy and less conservatism and is
easy for digital implementation. A numerical simulation and a quadruple-tank benchmark are used to demonstrate
the effectiveness and superiority of the proposed method."
Discrete-time observer, fault estimation, nonuniform sampling, polytopic uncertainty.