Abstract: Affine formation control can generate and transform the overall formation by only using the configurations of some key nodes, featuring high flexibility and good scalability. For the affine formation control problem of fixed - wing UAV swarms, an affine formation hierarchical control scheme is designed, which includes leader cooperative path following, follower tracking and colli-sion avoidance. This scheme divides the swarm into a leader layer and a follower layer: multiple leaders cooperatively generate the reference configuration required for the swarm formation while following the preset path, followers only need to track the desired positions in the affine formation spanned by the leader positions. Meanwhile, through collision - avoidance control, each UAV in the swarm can avoid environmental obstacles and inter - UAV collisions. Compared with existing algorithms, this method has a higher obstacle - avoidance success rate, can achieve inter - UAV collision avoidance, and the convergence speed of the follower tracking error is faster. Furthermore, a software - in - the - loop simulation of six UAVs is completed on the XTDrone platform built based on ROS and Gazebo. In the simulation, UAVs can form the desired affine formation and fly safely without collisions throughout the process. The relevant codes have been open - sourced.

Key words: Fixed-wing UAV swarm, Affine formation control, Leader-follower method, Cooperative path following, Collision avoidance