Spacecraft attitude tracking control based on MPC and fractional-order sliding mode control

Considering the problem of robust optimal finite-time attitude tracking for spacecraft, a unique characteristic of two advanced control methods, nonlinear fractional order sliding mode control (FOSMC) and linear model predictive control (MPC), combined in a two-layer controller was introduced. This method solved the global stability and robust attitude tracking problems of a group of reaction wheel-driven spacecraft in near-polar orbit under the action of unknown disturbances and uncertainties. The FOSMC controller guaranteed the robustness of the three-axis attitude tracking at suitable target points in the presence of disturbances and uncertainties. The two-layer controller part took into account the advantages of MPC technique to predict the attitude motive and constraints to provide the optimal target point required by the FOSMC controller. Finally, the reliability and superiority of the proposed method were verified by simulation results.