Adaptive backstepping control for reentry attitude of near space hypersonic vehicle with input saturation

This paper proposes a robust adaptive control scheme using backstepping method with dynamic surface technique for re-entry attitude tracking control of near space hypersonic vehicle (NSHV) in the presence of model uncertainties, external disturbances and input constraints. To estimate the unknown upper bound of the compound uncertainties, the novel robust adaptive laws are designed firstly. The “explosion of terms” problem inherent in conventional backstepping method is eliminated by the filter, and the errors caused by the filter are considered during the stability analysis. Additionally, to handle the input saturation problem, some rational signals are generated to compensate for the effect of the saturation in the dynamic systems by designing an auxiliary system. It is proved that the developed control scheme can guarantee that all signals of the closed-loop control system are uniformly bounded stable. Finally, simulation results are presented to illustrate the effectiveness of the proposed adaptive backstepping tracking control schemes.