UIO approach for estimation of nonlinear components behavior

Abstract

The main purpose of this paper is to present a method for estimating nonlinear parameters of dynamical systems using the concept of unknown input observer dedicated to linear systems. The bond graph approach is used due to its structural and causal properties and since each component can be precisely isolated using Fault detection and Isolation step. Three main points are developed and applied to a flexible joint robot link: modeling of a nonlinear component as a linear one with one unknown input, application of an unknown input observer with estimation of the nonlinear component behavior and estimation of variables of the model with application of a flat control.