Fault Tolerance Controller Design for the Safety Flight of the Quadcopter: Theory and Implementation

As for the actuator faults, modeling uncertainties, and unknown external disturbances may pose significant risks to the safe and reliable operation of quadcopters. In this paper, a disturbance observer-based nonlinear fault-tolerant control strategy is proposed to overcome above limitations simultaneously. By compensating for the combined effects of these disturbances, the proposed strategy achieves high-accuracy trajectory tracking and robust performance. Lyapunov-based stability analysis is provided to ensure the convergence of the translational and attitude tracking errors to zero. Real-time flight experimental results demonstrate that the proposed control strategy can guarantee safe and reliable flight for the quadcopter UAV under the effects of partial loss of thrust, modelling uncertainties, and unknown external disturbances.