Nonlinear Fault-Tolerant Control for Hypersonic Flight Vehicle With Multi-Sensor Faults

This paper presents a nonlinear fault-tolerant control (FTC) and sensor fault diagnosis for longitudinal dynamics of hypersonic flight vehicle. A nominal sliding mode control is developed to track the reference command of velocity and altitude on the basis of an affine nonlinear dynamic model. A nonlinear adaptive observer is proposed to estimate the fault in velocity system. The fault in altitude system is estimated using the coupling item as an estimation item through a backstepping sliding-mode observer to achieve an estimation performance better than that of the original adaptive observer. The estimation results are used to design a nonlinear FTC to compensate the multi-sensor faults. The stability of the controller is analyzed through Lyapunov theory. Numerical simulation results demonstrate the validity and robustness of the proposed controller and observer.