Sliding-mode-differentiator-based robust backstepping control of air-breathing hypersonic vehicles

A sliding-mode-differentiator-based robust backstepping controller was designed for air-breathing hypersonic vehicles with aerodynamics, propulsion and structural flexible dynamics couplings. Virtual and actual control laws were designed based on backstepping and dynamic inversion design procedure respectively. Sliding mode differentiator was introduced to obtain the derivatives of virtual control laws, which avoids the explosion of differentiation terms in the traditional backstepping control. A nonlinear disturbance observer, based on sliding mode differentiator, was introduced to estimate and compensate the model uncertainties of precisely, which enhances the controller's robustness. Simulation results demonstrate the effectiveness of this controller in tracking velocity and altitude commands in the presence of model uncertainty and flexible dynamics. ©, 2015, Journal of Solid Rocket Technology. All right reserved.