Robust state and unknown input estimation for nonlinear systems characterized by incremental multiplier matrices

Abstract

A systematic design method for robust state and unknown input estimation using sliding mode observers is proposed for a class of nonlinear systems with bounded unknown inputs. The considered nonlinearities satisfy a set of matrix inequalities known as incremental quadratic constraints. The proposed observer is constructed by solving a set of linear matrix inequalities guaranteeing global ℒ ∞ stability with a specified performance level. Conditions are given under which the proposed observer can reconstruct the unknown input. The effectiveness of the proposed observer is demonstrated on a simulation example.