Distributed predefined-time robust adaptive control design for attitude consensus of multiple spacecraft

This article investigates the distributed predefined-time attitude consensus of multiple rigid spacecraft under inertia uncertainties and external perturbations over directed communication topology. First, a distributed predefined-time observer is constructed for each follower spacecraft to estimate the virtual leader’s attitude, velocity, and acceleration. Then, based on the recovered information, a predefined-time nonsingular terminal sliding mode (NTSM) controller is developed for each follower spacecraft to fulfill the local attitude and velocity tracking. The predefined-time NTSM controller is strongly robust against uncertainties and perturbations but owns the undesirable chattering phenomena. To overcome such problem, an adaptive version of the predefined-time NTSM controller is carried out by incorporating with the parametric adaptation mechanism to identify the total disturbance. In this manner, the predefined-time adaptive NTSM controller has no chattering phenomenon and can maintain the high tracking accuracy simultaneously. Lastly, comparative simulations verify and highlight the main results.