Abstract: A distributed coordination control method based on artificial potential function and nonlinear disturbance observer is proposed to avoid collisions and preserve network connectivity for leader-follower spacecraft formation flying. By adding an attractive potential function to the distributed controller, the communications network can be connected at all time if the initial network is connected. Since the leader’s state is only known by its neighbors, a distributed velocity observer is designed to estimate the leader’s state for all followers. Finally, a nonlinear disturbance observer is integrated with the distributed controller to improve the accuracy of formation. The simulation results show that the proposed method can not only realize the collision avoidance between spacecraft under the premise of tracking the velocity of the leader, but also ensure the connectivity of the communications network during formation flying.

Key words: Spacecraft formation control, Leader-follower formation, Connectivity preservation, Collision avoidance, Nonlinear disturbance observer