Constraints-Aware Trajectory Tracking Control of Spacecraft Attitude using LPV and MPC

This paper presents an approach for trajectory tracking of quaternions representing spacecrafts attitude. A nonlinear controller is applied to a time-varying error system to track realizable trajectories of quaternions. The resulting closed loop is linearized leading to a linear parameter varying system (LPV), which is then used to analyze the closed loop and parameterize the nonlinear controller. Additionally, an outer-loop controller is applied to achieve objectives beyond closed-loop stability. Results demonstrate the effectiveness of the overall controller with two different linear controllers, LQR and MPC, for improving attitude control performance and input constraint satisfaction, respectively.