Using Tracking Differentiators in Designing Nonlinear Disturbance Observers for Uncertain Systems

Abstract

Using Tracking Differentiators in Designing Nonlinear Disturbance Observers for Uncertain Systems<br />Naser Kazemzadeh, Saeed Barghandan<br />Abstract<br />In the present paper, a practical designing method has been proposed for a novel class of NDOs based on TD. Such NDOs can nearly estimate all uncertain disturbances (specifically disturbances without prediction information). Regarding the outstanding performance of TD filter not requiring a precise dynamic model, the proposed NDO can estimate external disturbance and not modeled dynamics. The results showed the superiority of the proposed method in estimating disturbance and improvement of control quality.<br />Keywords: non-linear systems, uncertain disturbances, non-linear disturbance observer (NDO), tracking differentiator