Decentralized H_∞ control for attitude coordination of spacecraft formation

In this paper, a robust H_∞ decentralized controller is proposed for attitude coordination of spacecraft formation flying with external disturbance based on the relative attitudes and angular velocities of neighboring spacecraft. The controller is composed of nonlinear terms for performance enhancement and linear terms for attitude coordination and stabilization. The proposed control method guarantees the attitude alignment with zero final angular velocity and robust disturbance attenuation for spacecraft formation when the communication topology is connected. A feature of the proposed approach is that the robust H_∞ controller parameters can be obtained by solving linear matrix inequalities (LMIs), which makes the design more transparent. Finally, the numerical simulations of a spacecraft formation are provided to show the effectiveness of the proposed consensus algorithm.