Full- and reduced-order observer design for rectangular descriptor systems with unknown inputs

In this paper, methods are proposed to design Luenberger type full-and reduced-order observers for rectangular descriptor systems with unknown inputs. These methods are based on the effect of pre- and post-multiplicative operation of a linear transformation, derived here by means of simple matrix theory. Sufficient conditions for the existence of observers are given and proved. Numerical examples are given to illustrate the effectiveness of the proposed method

On parameterization design for linear observers

In this paper, the design of observers is further investigated via the parameterization technique. Two new observer parameterizations are addressed related to nonminimal reduced-order state observers. The known results in the references available can be obtained as particular results from the present parameterizations. For plants with input disturbances, parameterizations of estimation error dynamics are derived, providing useful tools for the design of robust optimal observers. An illustrative example is given for describing the parameterization procedur