-In this paper a design procedure for construction of reduced order unknown input observer, for linear time invariant system subjected to unknown input is presented based on generalized matrix inverse. Das & Ghosal observer is extended and used for this purpose. A condition is proposed and to be satisfied to develop such an observer. Finally an illustrative numerical example of a class of guide...

In this paper, the design of an unknown input observer is considered. The main contribution consists in the obtention of a sufficient condition to design an observer which estimates a part of the state independently of the knowledge of some inputs. Based on the geometric approach, a sufficient condition for the existence of an unknown input observer for state affine systems up to output injecti...

In this paper, we extend existing theory on nonlinear unknown input observer design to a wider class of nonlinear systems where the systems are subject to unknown input and output disturbances and experience faults. The approach used is to decouple the faults and unknown disturbances from the rest of the system through a series of transformations on state and output equations. Once total distur...

In this paper, a state and unknown input observer is proposed for discrete-time linear systems with bounded unknown inputs and measurement disturbances. The design procedure is formulated using a set of linear matrix inequalities, and leverages delayed (or fixed-lag) estimates. The observer error states and/or user-defined performance outputs are guaranteed to operate at pre-specified performan...