UAV cooperative path planning

Path planning arid coordination of multiple unmanned air vehicles, so as to jointly reach a target area while minimizing the flight's exposure to radar is addressed. A hierarchical decomposition approach is pursued. The optimal path planning for a single vehicle is performed to minimize exposure while a timing constraint is imposed. Each vehicle plans it's own path. The path planning consists of a two step procedure. First, a polygonal path to the optimal path is obtained. Second, the initial path is refined to a flyable path by acknowledging maneuverability constraints. The coordination of the timing of the vehicles' arrival at the target area is performed by the higher level coordination agent. The coordination agent calculates a team estimated time of arrival from a sensitivity function that is calculated and communicated by each of the UAVs. This approach is illustrated in a simulation of a simplified scenario where three UAVs are coordinated to arrive at the target area simultaneously. Popup threats are introduced that result in dynamic inflight replanning. Simulation results show that coarse grid planning and decentralized coordinated control can rapidly respond to new threats while satisfying rigid rendezvous timing constaints.