Attitude-Position Integrated Control for Spacecraft Formation With Predefined-Time Convergence

This article investigates the attitude-position integrated control of spacecraft formation in the presence of inertia uncertainties and external disturbances. The mathematical model of the spacecraft formation attitude-position integrated control system is established using dual quaternion representation. A novel predefined-time extended state observer (ESO) is developed to estimate the total perturbation, which includes both inertial uncertainties and external disturbances in the system model. Compared with existing predefined-time ESOs, the proposed observer eliminates redundant differential terms and provides a more rigorous theoretical proof. Based on the estimates obtained from this predefined-time ESO, a predefined-time attitude-position integrated control scheme for spacecraft formation described by dual quaternions is proposed for the first time. Furthermore, the closed-loop system's predefined-time stability is proven using Lyapunov stability theory. Finally, a series of comparative simulations validates the performance and effectiveness of the proposed predefined-time ESO and the presented control strategy.