Sensor and actuator fault detection, isolation and system reconfiguration in flight control system using unknown input observers

Automatic flight control systems fairly lighten the pilots' workloads. However, in these systems, sensors, actuators and control surface failures can cause undesirable results such as aircraft accidents to happen. It is possible to tolerate the failures in flight control systems by using what is known in literature as fault tolerant control which makes the operations of systems possible against some types of failures. In the decision making process of the control system, the detection of the failure can be performed by using full-order observer, reduced- order observer or unknown input observer which analyse the difference between the real and estimated states known as residual. In the isolation stage, the place of the faulty component could be determined exactly by using Dedicated Observer Scheme (DOS) or Generalized Observer Scheme (GOS). In this thesis, using unknown input observers, detection, isolation and reconfiguration stage of the failures of the sensor or actuator which take place randomly in flight control system are simulated.