Attitude Control Design for Hypersonic Reentry Vehicles Subject to Control Direction Reversal via Sliding Mode Approach

This paper investigates the control direction reversal issue for the attitude control design for hypersonic reentry vehicles, and proposes a novel sliding mode control law which addresses the control direction switching and strong robustness requirement simultaneously. Firstly, the disturbance observer is introduced to estimate the unmatched uncertainties in the attitude model of hypersonic reentry vehicles, and then a periodic function-involved sliding mode control is presented and the bounded stability of the closed-loop system is guaranteed via Lyapunov stability theory. The merits of the proposed method lie in that the closed-loop system is stable even under the unknown control direction reversal, and the unmatched uncertainties can be addressed by the disturbance observer. Finally, the simulation verifies the effectiveness and superiority of the proposed control .