Online Control Strategies for Highly Coupled Cooperative UAVs

The underlying problem is how to cooperatively use unmanned aerial vehicles (UAVs) to generate a coherent phantom track for a radar network to make it track a vehicle that does not exist. The UAVs need to plan a phantom track that is feasible given challenging nonlinear constraints on speed and heading, and optimal in terms of their aggregate costs and some global costs on the phantom. Models are formulated for the UAVs, wind, and the phantom. We develop practical methods for guiding the phantom and UAVs by first using optimal control and then either 1) adding smooth penalty functions to the cost, or 2) using control parametrization. The first method is compared through simulations with the second, which deals with state constraints more efficiently. The results are useful as a benchmark and for comparing more heuristic cooperative control algorithms. Because of its performance and fast solution times, the second method may also be used online.