Robust free-time-stable fault tolerant control for rigid satellite attitude system with output constraint

This article investigates the robust fault tolerant control strategy for a rigid satellite attitude system with external disturbance and actuator fault while the predesigned output constraint is taken into consideration. Based on the interval observer technique, an identical faulty signal reconstruction is first realized by utilizing pure mathematical calculation. Then, to guarantee the desired output constraint, the proposed prescribed performance fault tolerant control framework is constructed with a novel error interval representation which not only reduces the computation burden but also simplifies the output constrained controller design. In addition, by comparing with the existing finite/fixed time control method, the setting time for this control strategy can be assigned freely. The stability of the whole method is guaranteed by Lyapunov method. Finally, simulation results including comparisons with existing work show the effectiveness and advantages of the proposed approach.