Full-Order Sliding Mode Control for the Attitude of the Spacecraft under Input Saturation

This paper proposes a robust finite-time attitude controller for spacecraft with input saturation by utilizing the full-order sliding mode control (FOSMC). Using the hyperbolic tangent function and homogeneity theory, a new full-order sliding mode (FOSM) surface was developed which makes the states of the system reach the equilibrium point in finite time. Based on the strengths of the designed FOSM surface, a robust attitude controller that makes the errors of the system converge to zero in finite time was developed for spacecraft without chattering and singularity problems. The effectiveness of the presented controller was verified via rigorous theoretical analysis and simulation results.