A sliding mode technique for reconstruction of unknown control input in linear systems

Abstract

The unknown input estimation problem for linear dynamic systems exposed to the disturbances is studied in the paper. A novel approach to designing sliding mode observer is suggested for systems not satisfying matching, minimum phase, and detectability conditions. To apply this approach, the reduced-order model of the original system is used. Such a model allows to reduce the dimension of the sliding mode observer, besides the restrictions placed on the original system are relaxed.