State and sensor fault interval estimations for discrete-time systems

In this paper, the problem of state and sensor fault estimations by using interval observer for discrete-time systems is investigated. First, the original system is transformed into a descriptor system without sensor faults. Second, a non-feed-back framework interval observer (NFBFIO) is constructed for non-negative/negative systems. Third, by using a linear transformation, a feed-back framework interval observer (FBFIO) is constructed for observable systems. Finally, two simulation examples show the validity and effectiveness of the proposed methods.