Adaptive fuzzy backstepping control for attitude stabilization of flexible spacecraft with signal quantization and actuator faults

In this study, the fault-tolerant attitude control of flexible spacecraft is investigated over digital communication channels, where a uniform quantizer is considered with respect to the sensor signals and controller indexes. Further, an adaptive fuzzy backstepping control strategy has been developed for the considered attitude stabilization issue, where the adaptive fuzzy logic method is used to approximate the rigid-flexible coupled nonlinearity of the spacecraft. In this design, the online adjusting quantizer parameters are injected into the controller gains to simultaneously compensate for the quantization errors and time-varying actuator faults. In the proposed control method, the attitude stabilization task is achieved in the presence of external disturbances, time-varying actuator faults, and signal quantization. Finally, the practical examples are compared to demonstrate the effectiveness of the proposed control strategy.