Abstract

This thesis presents the theoretical development, simulation study and flight tests of a Lyapunov-based control approach for the Fault Tolerant Control (FTC) of a quadrotor unmanned aerial vehicle (UAV). Based on the derivation of nonlinear model of the dynamics of the quadrotor UAV, a Lyapunov-based control approach with fixed controller gains is proposed and firstly demonstrated through simulations of the quadrotor UAV for handling system parameter uncertainties. Secondly, this proposed Lyapunov-based approach with the selected controller gains is applied as a fault tolerant controller in the framework of a passive Fault Tolerant Control System (FTCS), for handling less severe faults occurring in the quadrotor UAV. Thirdly, the proposed new controller by Lyapunov-based adaptive control method for fault tolerant control of the quadrotor UAV is proposed to handle more severe faults. Finally, the Lyapunov-based control method has been implemented to the test bed, Qball-X4 Unmanned Aerial Vehicle, and the acceptable performances on altitude control have been achieved. In the thesis, simulation and flight testing results demonstrate that the FTCS with the Lyapunov-based approach has certain robustness for most of partial losses. However, the FTCS with Lyapunov-based adaptive control approach has advantages in accommodating more severe faults for, which may not be addressed by the Lyapunov-based approach