Dual hybrid non-fragile control for integrated electromagnetic docking and separation of spacecraft

This paper proposes a dual hybrid non-fragile control strategy for spacecraft electromagnetic docking and separation. The strategy addresses challenges arising from inherent fragility and multi-source complex disturbances, including external disturbances, unknown masses, elliptical eccentricities, and input constraints. Firstly, the dynamics model of spacecraft electromagnetic docking and separation is described and analyzed, incorporating these disturbances. Subsequently, the dual hybrid non-fragile control strategy is developed. It utilizes a hybrid non-fragile disturbance observer to estimate the disturbance, which then compensates for the non-fragile controller, effectively handling coexisting gain perturbations in both observer and controller. Then, a theorem is presented with a detailed Lyapunov-based proof to establish the ultimately uniformly bounded stability of the closed-loop system. Finally, simulations and comparative analyses demonstrate the strategy's effectiveness and superiority when comprehensively considering disturbances and perturbations.