Singular Perturbation-Based Fault-Tolerant Control of the Air-Breathing Hypersonic Vehicle

This article studies the fault-tolerant control issue of the air-breathing hypersonic vehicle subject to the actuator fault. Through singular perturbation modeling, the longitudinal dynamics of the vehicle can be transformed into a three-time-scale singularly perturbed system. A new nonlinear diagnostic observer is designed to estimate the actuator fault first. Then a cyclic-small-gain principle-based distributed fault-tolerant control strategy is developed by regarding the singularly perturbed system as an interconnected system with three subsystems. The proposed distributed fault-tolerant controller can achieve the input-to-state stability of the longitudinal motion at the cruising condition with respect to the fault estimation error. The simulation results show the effectiveness of the proposed method.