Research On U-Model-based Fault-Tolerant Flight Control Systems

During flight,aircrafts encounter complex and volatile ambient environment.At the same time,the internal components of aircrafts might malfunction due to abrasion and other reasons which will affect the stability and reliability of the flight control system to some extent.Therefore,this thesis proposes a new controller design method by employing the idea of fault-tolerant control for the flight control system in order to improve the stability of the control systems and ensure the safety of aircrafts.This thesis combines U model with fault-tolerant control to design controllers for Single Input Single Output(SISO)systems and Multiple Input Multiple Output(MIMO)systems.When designing the controller for SISO systems,the quadrotor flight control system is used as the controlled object.When the system fails because of the actuator failures,the sliding mode control method is used to improve the robustness of systems which meets the performance requirements.Finally,it is verified by simulation.When designing the controller for MIMO systems,the longitudinal flight control system of Boeing 747 is used as an example.When the system suffers the disturbances,the thesis uses U-model-based generalized predictive control(GPC)method to design the controller to improve the passive fault tolerance of systems.Finally,this method is verified by simulations.The U-model-based controller design method can be adapted to more controlled object model,and it is more convenient for the controller design.It can be combined with fault-tolerant control to improve the fault-tolerant performance.