Collision avoidance for quadrotor UAVs transporting a payload via Voronoi tessellation

This paper is focused on the formation planning and control of an arbitrary number of quadrotors transporting a cable-suspended payload. A payload that is modeled as a point mass is connected to quadrotors via rigid links, and a desired trajectory of the payload is prescribed. Assuming that the location and shape of obstacles are available, the desired formation of quadrotors relative to the payload is constructed to avoid collision with the obstacles, via the centroidal Voronoi tessellation. Then, these are integrated with a geometric tracking control system. A numerical example illustrates that quadrotors transports a payload along a desired trajectory, while flying through a narrow gap between obstacles to avoid a collision.