Guaranteed state and unknown input estimations for linear time-invariant systems with direct feedthrough using interval observers
Résumé
In this paper, an interal observer for both state and unknown input estimation is proposed for a Linear Time Invariant (LTI) system. It generalizes previous work done on the subject. Such an observer is constructed under some specific conditions. Among those conditions, a rank condition is needed to ensure the independence between the state estimation and the unknown input. In this paper, former proposed rank condition is relaxed thanks to the use of another one, less restrictive. Moreover, the proposed observer can be applied for systems with the unknown input in both the state and measurement equations. Examples are given to discuss and illustrate the proposed approach.