Adaptive sliding mode back-stepping control for hypersonic flight vehicle with state constraints and unmodeled disturbances

This study presents a finite-time adaptive sliding mode back-stepping controller (FASMBC) for hypersonic flight vehicle (HFV), where the state constraints and unmodeled disturbances are considered. Firstly, the longitudinal model of HFV is decomposed into altitude subsystem and velocity subsystem. Then, sliding mode control and back-stepping logic based on barrier Lyapunov function are merged to design the robust controller for each subsystem. Besides, the adaptive strategy is applied to estimate the unmodeled disturbances. A tracking differentiator is introduced to avoid the "explosion of terms" problem involved in traditional back-stepping control. Finally, the simulation results is provided to illustrate the effectiveness of the proposed control scheme.