Adaptive fault-tolerant robust control for a linear system with adaptive fault identification

An integrated design of the adaptive robust control and the fault identification for a linear system with actuator faults is proposed. When actuators suffer from unpredicted faults, the proposed control strategy can track the actuator fault parameters adaptively without any prior fault information, and guarantee the robustness of the faulty system. An unknown input observer is designed to decouple the disturbance and the actuator faults. Then an adaptive control law with projection is presented to track the fault parameters. A new definition of robust H_∞-like performance is proposed to ensure that the system is robust for both exogenous disturbance and unpredicted faults. Then the adaptive robust control law is designed to guarantee the system satisfying the robust H_∞-like performance. Finally, the effectiveness of this control strategy is illustrated through the faulttolerant longitudinal control of the simplified F-18 aircraft model.