A reliable fault tolerant attitude control system based on an adaptive fault detection and diagnosis algorithm together with a backstepping fault recovery controller

This paper presents a practical solution to achieve a fault tolerant attitudecontrol system capable of fault detection and diagnosis (fdd). the novelty of ourproposed strategy is in the accurate modeling of satellite dynamics by the takagi-sugenomethod. based on this model, an adaptive observer has been utilized to achieve faultdiagnosis in reaction wheels of the attitude control system (acs). for this, the occurredfaults in reaction wheels have been estimated using an adaptive algorithm which providesfault detection and identication abilities. moreover, in this paper, a recovery algorithmhas been utilized, combined with fault detection and identication algorithm, to provide anadvanced decision support system. in this regard, for undertaking the remedial actions, abackstepping feedback linearization control law has been considered in which the estimatedfault has been utilized. accordingly, the boundedness of the attitude control error isguaranteed, despite actuators fault. the developed algorithms provide a signicant degreeof autonomy to eectively handle satellite operation in the presence of acs faults, withoutthe ground segment intervention. through extensive simulation results, the designedalgorithms are shown to be robust and accurate. also, designed algorithms are assessedthrough hardware in the loop test bed to evaluate their functions in an experimentalsituation.