Robust backstepping control of reusable launch vehicle in reentry phase based on disturbance observer

The attitude tracking control problem of reusable launch vehicle (RLV) in reentry phase is investigated in this paper. The control-oriented model is firstly developed from the attitude model, and it is decomposed into two subsystems on the basis of the engineering backgrounds of RLV. Via backstepping design procedure, sliding mode control scheme is designed while the lumped uncertainty is estimated by the disturbance observer at the level of control design. To sequel, stability analysis is shown in the framework of Lyapunov theory. At last, to evaluate the effectiveness of the proposed control scheme, simulation is done for the 6-DOF reentry model.