A Safe Flight Method for Swarm Formation Based on Virtual Center in Complex Environments

Using multi-drones formation to transport heavy objects with ropes has become a common method, addressing the limited load-carrying capacity of a single drone. To avoid rope entanglement during transportation, the formation configuration needs to be maintained. However, existing formation control strategies emphasize formation stability while neglecting obstacle avoidance capabilities. To address this issue, this paper proposes a safe flight method for drone swarms in complex environments based on a virtual center. The virtual center of the formation is calculated based on the positions of each drone within the swarm. Following this calculation, a safe and feasible trajectory for the virtual center is computed using an optimization approach. Subsequently, a consensus control strategy is proposed considering the positional offsets between drones and the virtual center to ensure formation stability during flight. Additionally, we propose an affine formation transformation centered around the virtual center. This transformation enhances swarm navigation safety in obstacle-dense environments and mitigates the risk of rope entanglement. Finally, simulation experiments validate the feasibility of the proposed method, demonstrating that the swarm formation can fly safely and stably in complex environments.