Trajectory planning and re-planning for fault tolerant formation flight control of quadrotor unmanned aerial vehicles

This paper proposes an approach for fault tolerant control of quadrotor UAVs in formation flight. The fault tolerance is achieved by changing the reference trajectories of the entire formation so that to allow the damaged UAV to follow the healthy ones. For this purpose, the virtual structure formation framework is adopted and differential flatness is employed to find the relation between the applied control inputs and the reference trajectories. Simulation results for three UAVs in formation are given to demonstrate the effectiveness of the proposed approach.