Decentralized attitude synchronization of spacecraft formations under complex communication topology

The attitude synchronizing of formation flying spacecrafts is an essential ingredient in almost all practical situations. However, thus far no control scheme was proposed for synchronizing the attitude of multiple spacecraft without a prescribed reference attitude in the presence of disturbance torques and limited communication topology. A decentralized robust attitude control law is proposed in order to guarantee spacecraft attitude synchronization under external disturbances in the absence of a common reference attitude or any other hierarchy in the formation. The proposed controller is effective with a large range of communication topologies and is designed using the absolute angular velocity and attitude quaternion. The control scheme is robust against environmental disturbance torques. The convergence and stability of the proposed controller for the resulting closed-loop system are proven theoretically. Numerical simulations are included to validate the analytical results.