Co-operative path planning of multiple UAVs using Dubins paths with clothoid arcs

This paper describes co-operative path planning of a group of unmanned aerial vehicles (UAVs). The problem undertaken for this study is that of simultaneous arrival on target of a group of UAVs. The problem of path planning is formulated in order to produce feasible (flyable and safe) paths and the solution is divided into three phases. The first phase is that of producing flyable paths, the second is to add extra constraints to produce safe paths that do not collide with other UAV members or with known obstacles in the environment, and the third is to produce paths for simultaneous arrival. In the first phase, Dubins paths with clothoid arcs are used to produce paths for each UAV. These paths are produced using the principles of differential geometry. The second phase manipulate these paths to make them safer by meeting safety constraints: (i) to maintain minimum separation distance, (ii) to produce non-intersection of paths at equal lengths, and (iii) to fly-through intermediate way-points/poses. Finally, in the third phase, the simultaneous arrival is achieved by making all the paths equal in lengths. Some simulation results are given to illustrate the technique.