On the practical estimation of unknown inputs for polytopic LTI systems. Issue 4 (11th January 2018)

• Record Type: Journal Article
• Authors: Torres Zúñiga, Ixbalank; Vargas, Alejandro; Moreno, Jaime A.
• Is Part Of: IET control theory & applications. Volume 12:Issue 4(2018)
• Page Start: 466
• Page End: 476
• Publication Date: 2018-01-11
• Subjects: linear systems -- observers -- robust control -- uncertain systems; unknown input estimation -- polytopic LTI systems -- real‐time monitoring -- unknown input reconstruction -- coupled robust observer -- state vector estimation -- uncertain linear systems -- time invariant systems -- Luenberger observer -- super‐twisting observer -- semidefinite optimisation problems -- nonlinear biological system; Control theory -- Periodicals; Automatic control -- Periodicals; 629.8312
• DOI: 10.1049/iet-cta.2017.0856
• Languages: English
• ISSNs: 1751-8644

Abstract

Abstract : Reconstruction of unknown inputs is an important issue in real‐time monitoring when they cannot be directly measured. This study proposes a coupled robust observer to estimate both the state vector and the unknown input of uncertain linear and time invariant (LTI) systems. A Luenberger observer is first considered to estimate the state vector and then, a super‐twisting observer uses the precedent estimations to reconstruct the unknown input. Two semi‐definite optimisation problems are proposed to compute the observer gains. The feasibility of the strategy is illustrated by the two examples, one of them a non‐linear biological system.