Adaptive fault-tolerant attitude control for reentry vehicle involving actuator saturation

Abstract

Many control methods are used in attitude control of reentry vehicle, such as optimal control and classical control methods. However, those control laws may not work effectively if the attitude system is confronted with actuator faults and saturation. This paper proposes an adaptive fault tolerant attitude control method for the reentry vehicle's attitude control system, by combining the radial basis function network technology with adaptive fault tolerant control method. We simultaneously considered actuator fault, actuator saturation, time varying unknown disturbances and uncertainties when designing the control method. First, we set up the reentry attitude dynamic model concerning actuator fault; second, a finite-time H∞ adaptive fault-tolerant attitude controller is introduced to deal with the actuator fault, saturation, unknown disturbances and uncertainties of the reentry vehicle system; we proved the stability of our proposed adaptive attitude fault-tolerant controller through the Lyapunov function and the linear matrix inequality method. Finally, the effectiveness of such adaptive fault-tolerant control method has been identified by numerous simulation results. The simulation results show that our proposed method can not only effectively deal with actuator fault in the attitude control system, but also has very good robustness for actuator saturation, time varying unknown disturbances and uncertainties.