Task assignment for cooperating UAVs under radio propagation path loss constraints

Unmanned Aerial Vehicles (UAVs) may be used for surveillance of power lines and railways and topological surveying to support the planning of new road routes. Motivated by these applications we will in this paper formulate a Mixed Integer Linear Programming (MILP) problem to be used for coarse offline path planning of such missions. Many of the missions rely on real time transfer of sensor data back to a human operator at the base station, to allow for intervention if the collected data show something of particular interest. In our approach we allow for the use of multiple UAVs where one or more of the vehicles also can be used as relay nodes for the transmitted data. The path obtained by solving the optimization problem is analyzed using a realistic radio propagation path loss simulator. If the radio propagation path loss exceeds the maximum design criterion the optimization problem is solved again with stricter communication constraint, and the procedure is continued in an iterative manner until the criterion is met.