Adaptive non-singular fault-tolerant control for hypersonic vehicle with unexpected centroid shift

A study on hypersonic vehicle (HSV) with centroid shift and actuator fault is made to investigate the adaptive fault-tolerant control for stability recovery of HSV operating in off-nominal conditions. Based on the modelling and analyzing the influence of centroid shift and actuator fault on HSV, the centroid shift can cause system uncertainty, variation of inertial matrix, eccentric moment and strong coupling between the longitudinal and lateral motions, resulting in the high demand for controller. According to the difference of response time, the attitude system of HSV is divided into slow and fast loop. For handling the effect of centroid shift, actuator fault and external disturbance, an improved sliding mode controller combined with adaptive estimator is designed for the slow-loop. Nonlinear general predictive controller (NGPC) assisted by adaptive radial basis function neural network (RBFNN) is developed for fast-loop. In addition, the nonsingular improvements to fast-loop controller are also made to cope with such the problem caused by the estimation of inertial matrix. The stability and tracking ability of the system are analyzed by the Lyapunov theorem of stability. At last, the simulation results show that the fault-tolerant control algorithm provided in this paper is very effective.