Decentralized robust attitude tracking control for spacecraft networks under unknown inertia matrices

This article investigates the quaternion-based attitude tracking problem for spacecraft networks, where the interaction topology among spacecraft switches periodically and inertia matrices are totally unknown. The tracking error dynamics is modeled. A class of robust attitude coordination controller without introducing the information about external disturbances is proposed. Using the Lyapunov method and graph theory, it is proved that the controller can guarantee a group of spacecraft to track the time-varying reference attitude. Further, the tracking error can be adjusted by designers to satisfy different requirements of control accuracy. Finally, simulation results are presented to illustrate that the designed control law is successful in achieving high tracking performance, even in the presence of unknown external disturbance torque, unknown inertia matrices and switching interaction topology among spacecraft.