Multi-target surrounding control of spacecrafts with sensor faults: A quantitative prescribed performance approach with event-triggered mechanism

This paper proposes a surrounding control method for spacecraft formation to surround multiple targets, considering some unexpected incidents, such as external disturbances, input saturation, and position sensor faults. Firstly, a distributed estimator is introduced to approximate the center of the targets. Then, a neural network-based state observer is designed to handle model uncertainties, and an adaptive parameter law is employed to compensate for the fault coefficients of the spacecraft position sensors. Secondly, a quantitative prescribed performance function (QPP) is devised to ensure overshoot, convergence time, and steady-state accuracy of the tracking error. Furthermore, while maintaining tracking performance, a dynamic event-triggered mechanism is combined to reduce the data transmission pressure. Finally, theoretical analysis and simulation results are presented, demonstrating that the spacecraft formation can effectively encircle the moving targets, verifying the performance and efficiency of the proposed scheme.