A Robust Sensor Fault Reconstruction Based on a New Sliding Mode Observer Design Method for Uncertain Delayed Systems : A Satellite System Application

Abstract

In this paper, we present a robust sensor fault reconstruction scheme to an uncertain time-delay satellite system using a new Sliding Mode Observer (SMO). Indeed, obtaining a robust sensor fault reconstruction, taking into account the uncertainty and the time-delay, is a difficult task. Therefore, to overcome this difficult, a virtual augmented system is established in which the sensor fault in the real system is treated as actuator fault. For this virtual augmented system a new SMO design method is proposed. To obtain this observer, the SMO concept, a Lyapunov-Krasovskii approach and the Linear Matrix Inequality (LMI) optimization are derived to guarantee the stability of the estimation error dynamics and compute the SMO gains. Consequently, applying the developed SMO, the Bounded Real Lemma (BRL), the H_inf concept and a Lyapunov-Krasovskii functional, a robust sensor fault reconstruction is obtained. A satellite system is included to show the efficiency of the proposed methods.