Active robust fault-tolerant H∞ control design based on an adaptive fault observer

An active adaptive H∞ control for a linear system with actuator faults is presented by using two adaptive control laws. When actuators suffer from faults, the proposed control can track the fault parameters adaptively without any prior fault information and guarantee the H∞ performance of the faulty system. One of the adaptive control laws based on unknown input observer is used to identify the fault parameters, and then the other one is used to make the system satisfy H∞ performance. The controller is designed in terms of linear matrix inequalities. Finally, the effectiveness of this method is illustrated through the fault-tolerant longitudinal control of F-18 aircraft.