Pairwise Control In Unmanned Aerial Vehicle Swarm Flocking

Abstract Inspired by the natural phenomenon that pair-bonded jackdaws fly together within a flock, a new cooperative model and control method with pairwise structure in the swarm flocking is proposed to perform proximity missions such as air refueling, data exchange and coordinated operations of two unmanned aerial vehicles in the swarm. A noval square-law error sliding mode surface and variable structure sliding mode controller are proposed, so that any two unmanned aerial vehicles in the swarm could converge to a specified relative distance. Based on this, the distributed control protocol is designed that integrates pairwise distance control and flocking control. It enables unmanned aerial vehicles to be paired in the swarm without disrupting the consensus of the entire swarm. Finally, two theorems are proved by Lyapunov stability theorem. The distance between paired unmanned aerial vehicles is exponentially convergent, and the swarm flocking is collision free. Swarm flight simulations based on particle motion model with number from 20 to 100 are respectively presented, as well as 10 unmanned aerial vehicles swarm flight simulations with quadrotor dynamics model. The simulation experiments have sufficiently verified the effectiveness and accuracy of the method. The results show that distance control could still be achieved in the extreme case that the paired unmanned aerial vehicles are at the farthest corners of the swarm.