State-reconstruction-based robust backstepping control of air-breathing hypersonic vehicles

A robust backstepping controller was designed based on state reconstruction for flexible air-breathing hypersonic vehicles considering that only the velocity, altitude and pitch rate were observable. Firstly, the controlled plant was rewritten as a strict feedback form, and the actual control laws and virtual control laws were designed based on dynamic inversion and backstepping respectively. Secondly, arctangent tracking differentiator was introduced to estimate the derivatives of virtual control laws and reconstruct the states of flight-path angle and angle of attack. Finally, in order to guarantee the backstepping controller' robustness, a new nonlinear disturbance observer was designed based on nonlinear-linear tracking differentiator to estimate and compensate uncertainties of the model precisely. Simulation results show that a high precise state construction can be obtained by the proposed strategy and the presented control methodology can provide a stable altitude and velocity tracking, and eliminate the influence of the uncertainties of the model. ©, 2015, Journal of Solid Rocket Technology. All right reserved.