Fault-tolerant anti-windup control for hypersonic vehicles in reentry based on ISMDO

Due to the extreme large flight scale of Hypersonic Vehicle (HSV), the system inevitably possesses strong nonlinearity, coupling, fast time-variability and is also sensitive to disturbance and fault. The method of external anti-windup system combined with the terminal sliding mode control law (TSMC) is presented for the nonlinear control problem under the restriction of control surfaces for HSV. It can realize the compensation for the control surface saturation and let the HSV smoothly track the command signals. Then, the improved sliding mode disturbance observer (ISMDO) is proposed to estimate unknown parameters and strong external disturbance as well as the unknown actuator fault. This method does not need the information of disturbance and the fault bounds and has fewer learning parameters, which makes it suitable for the real-time control. Finally, the simulation test of attitude control for the reentry HSV is conducted, and the results show the effectiveness and robustness of the proposed scheme.