Robust image-based coordinated control for spacecraft formation flying

•An integrated 6-DoF relative dynamic model for spacecraft formation flying (SFF) is built based on the 2D image features.•An image-based controller is presented for each follower spacecraft to achieve both relative position tracking and attitude synchronization with the leader.•The algebraic graph theory is combined with the image-based control scheme in the SFF mission.•The adaptive technique is integrated into the controller design to improve the robustness of the SSF system. This paper addresses a coordinated control problem for Spacecraft Formation Flying (SFF). The distributed followers are required to track and synchronize with the leader spacecraft. By using the feature points in the two-dimensional image space, an integrated 6-degree-of-freedom dynamic model is formulated for spacecraft relative motion. Without sophisticated three-dimensional reconstruction, image features are directly utilized for the controller design. The proposed image-based controller can drive the follower spacecraft in the desired configuration with respect to the leader when the real-time captured images match their reference counterparts. To improve the precision of the formation configuration, the proposed controller employs a coordinated term to reduce the relative distance errors between followers. The uncertainties in the system dynamics are handled by integrating the adaptive technique into the controller, which increases the robustness of the SFF system. The closed-loop system stability is analyzed using the Lyapunov method and algebraic graph theory. A numerical simulation for a given SFF scenario is performed to evaluate the performance of the controller.