Distributed Formation Flight for Fixed-Wing UAVs Based on Cooperative Moving Path Following under Wind Disturbances

This paper presents a distributed time-varying formation control protocol for fixed-wing unmanned aerial vehicles (UAVs) based on cooperative moving path following (CMPF) method. The UAVs follow the moving point on a pre-planned or real-time generated geometric path while respective fixed-wing vehicle achieves time-varying formation in the presence of wind disturbances. Different from the previous studies on path following problem, the fixed-wing UAVs in this paper form a distributed time-varying formation based on partially information between neighbor interactions. Firstly, by considering the complete kinematics for fixed-wing vehicle model, tracking error dynamics with reference to the Serret-Frenet frame of moving virtual point are derived. The criteria of virtual target selection is relaxed to general moving point rather than the closest trajectory projection while the singularity problem is avoided. Secondly, distributed extended state observers (DESOs) are designed to reconstruct the local states and wind disturbances simultaneously. Thirdly, observer-based controllers are proposed in distributed architecture to realize cooperative time-varying formation flight with the mismatched wind disturbances compensated in output channel with minimum norm. Finally, numerical simulations are provided to verify the effectiveness of proposed method.