PDE-model-based adaptive event-triggered fault-tolerant control for flexible spacecrafts with input saturation and communication constraints

This study investigates the fault-tolerant attitude and vibration control for flexible spacecrafts with input saturation and communication constraints. A flexible spacecraft is formulated using the ordinary differential equation (ODE) and partial differential equation (PDE), representing the attitude motion and structural vibration, respectively. To reduce the communication burden between the controller and actuators, an event-triggering mechanism with a relative threshold strategy is designed. Moreover, the control input is quantized using a hysteresis quantizer. Thereafter, based on the coupled ODE-PDE model, an adaptive event-triggered fault-tolerant control scheme is proposed using an auxiliary term and hyperbolic tangent function, which can compensate for the uncertainties stemming from time-varying actuator faults, input saturation, input quantization, external disturbance, and unknown inertial parameters. Finally, the system stability is analyzed using Lyapunov's direct approach, and the performance of the proposed control scheme is validated through numerical simulations.