Attitude Coordinated Tracking for Formation Spacecraft under a Directed Graph

In this paper we study the attitude coordinated tracking problem for formation spacecraft under a directed graph. We design a distributed coordinated tracking algorithm which guarantees all followers to track the leader. It is shown that the closed system is asymptotically stable as long as the directed communication topology characterizing the interaction among the followers and the leader contains a directed spanning tree. Then, we extend the distributed control algorithm to guarantee that the spacecraft maintain constant relative orientations with their neighbors. Finally, numeric simulations are provided to demonstrate the effectiveness of the proposed control algorithms.