Abstract: Aiming at the tracking control problem of the longitudinal channel of the hypersonic vehicle, a novel backstepping control method without online differentiation is proposed. Firstly, the vehicle dynamical model is divided into velocity subsystem and flight path angle (FPA) subsystem, and then the controller design for FPA subsystem is devised by adopting the backstepping method. The high order differentiator technique is utilized to construct the control law of the first derivative of the virtual command directly, which can avoid the “explosion of complexity” problem in existing backstepping method when calculating the first derivative of the virtual command. Meanwhile, this novelty can simplify the controller’s structure and decrease the number of controller’s parameters to be designed. Moreover, utilizing the tracking differentiator technique, some uncertainty observers are developed to accomplish the estimations of various model uncertainties for improving the controller’s tracking accuracy. Finally, the stability of the closed loop system is proved via the Lyapunov theory, and the effectiveness of the proposed method is verified through a comparative simulation experiment.

Key words: Hypersonic vehicle, Tracking control, Backstepping, Explosion of complexity, High order differentiator, Uncertainty estimation