Design and control of a modular multi-drone system with vertical assemble capability

A unmanned aerial vehicle (UAV) has limited payload capacity based on its design. This paper introduces a stackable UAV that can be assembled vertically. This, for example, can enable multiple UAVs to come together to carry a larger load. Firstly, a docking mechanism has been designed to dock multiple UAV modules into a UAV structure. Then, mathematical modeling of the UAV module and the UAV structure for the proposed system have been built. The second goal of this paper is to propose a novel PD controller gain calculation method. The purpose was not to retune the controller each time as the UAV number changes. As each UAV module is already tuned, this paper proposes a PD controller method in which the structure's control gains are calculated by the number of UAV modules and the parameters of each module. Simulation and stability analysis of the proposed controller and experiments with manufactured UAVs have shown the benefits and performance of the UAV structure, as its performance has been compared with a single UAV module. Moreover, unlike previous work in the literature, the payload performance of a vertical-assembled UAV structure has been examined.