Fault-Tolerant Control For Fixed Wing Unmanned Aerial Vehicle Via Adaptive Technique

With the development of avionics and computer technology,the fixed wing UAV has not only got large-scale developed in the scale,but also has a qualitative leap in the performance.The UAV is used more and more widely,which makes the safety and reliability requirements of UAV become higher and higher,so we have to design fault-tolerant tracking controller for UAV,which has certain fault-tolerant ability in fault mode to improve the safety and reliability of the aircraft.In this thesis,it is studied that the fault-tolerant control of fixed wing UAV.Firstly,this thesis introduces and analyzes the flight control system and the model,then the linear model and the fault model of UAV are established..Secondly,the direct adaptive fault-tolerant controller is designed by considering the faults of the actuator(control channel),the uncertainties and the disturbance of the system.A direct adaptive technique is used to design fault tolerant controller in order to modify the controller parameters online On the condition that the disturbance and deviation are only bounded,but not knowing the change,the effect of the disturbance and deviation caused by the disturbance and the deviation is completely compensated by the designed controller.In the end,the direct adaptive method is verified by the lateral motion equation of the UAV.Finally,a model reference adaptive method to deal with the tracking problem of UAV fault tolerance.The main research is the situation of the existence of system model matching uncertainty and the interference.At the beginning,the model reference adaptive is established for a trouble-free,and the reference model is completely followed.When uncertainty and disturbance in the system occur,the adaptive controller is redesigned.Combining adaptive direct method and the model reference adaptive thought,this thesis proposes the model reference adaptive fault tolerant controller to achieve full compensation for the disturbance and uncertainty,which not only can guarantee the system asymptotically stable,also ensure the system track the expected system stably.At last,the validity of the adaptive method is verified by the lateral motion equation of the UAV.