Publication

A novel unknown input observer design for nonlinear LPV systems

Journal Article (2025)

Journal

IEEE Control Systems Letters

Pages

1658-1663

Volume

9

Doc link

http://dx.doi.org/10.1109/LCSYS.2025.3580325

File

Download the digital copy of the doc pdf document

Authors

Abstract

This letter presents the design of an unknown input observer (UIO) for linear parameter-varying (LPV) systems, including nonlinearities that are assumed to fulfill one-sided Lipschitz quadratically inner-bounded (OSL-QIB) conditions. The proposed approach introduces a novel extension of conventional LPV frameworks by directly incorporating nonlinear terms, aiming to improve observer performance and reduce the modeling errors typically introduced during the transformation of a nonlinear system into its LPV counterpart. A key contribution of this letter is the development of a UIO design that avoids the state transformation step, which is often highly complex and only valid under restrictive assumptions such as a constant unknown input matrix D. By eliminating this constraint, the proposed observer design significantly enhances scalability and applicability to a broader class of systems. The performance and effectiveness of the approach are demonstrated through both a numerical example and a well-established open-channel flow benchmark: the Corning channel in California, USA.

Categories

control theory.

Author keywords

Fluid mechanics , LPV , material and energy balances , OSL-QIB , unknown input observer , OCIS

Scientific reference

J.P. Arango, L. Etienne, E. Duviella, K. Langueh, P. Segovia and V. Puig. A novel unknown input observer design for nonlinear LPV systems. IEEE Control Systems Letters, 9: 1658-1663, 2025.