This paper considers the fault estimation problem of nonuniformly sampled system in which sensorsampling is performed at aperiodic interval. After being discretized at sampling instant, the nonuniformly sampledsystem is modeled as an equivalent polytopic system with norm bounded uncertainties. A discrete-time time-varyingfault estimation observer with multiple design freedom is then constructed, and a sufficient condition given in linearmatrix inequality (LMI) is provided to obtain the constant filter gain and ensure not only the asymptotic stability offault estimation error but also the robustness of uncertainties. Compared with the existing observer designed basedon continuous-time delay approach, the proposed one has a better estimation accuracy and less conservatism and iseasy for digital implementation. A numerical simulation and a quadruple-tank benchmark are used to demonstratethe effectiveness and superiority of the proposed method.
This paper considers the fault estimation problem of nonuniformly sampled system in which sensorsampling is performed at aperiodic interval. After being discretized at sampling instant, the nonuniformly sampledsystem is modeled as an equivalent polytopic system with norm bounded uncertainties. A discrete-time time-varyingfault estimation observer with multiple design freedom is then constructed, and a sufficient condition given in linearmatrix inequality (LMI) is provided to obtain the constant filter gain and ensure not only the asymptotic stability offault estimation error but also the robustness of uncertainties. Compared with the existing observer designed basedon continuous-time delay approach, the proposed one has a better estimation accuracy and less conservatism and iseasy for digital implementation. A numerical simulation and a quadruple-tank benchmark are used to demonstratethe effectiveness and superiority of the proposed method.