Routing of Two Unmanned Aerial Vehicles with Communication Constraints

A novel GPS denied routing problem for UAVs is described, where two UAVs cooperatively navigate through an array of non-communicating Unattended Ground Sensors (UGS). Contact with UGS is strictly maintained, which allows the UGS act as beacons for relative navigation eliminating the need for dead reckoning. This problem is referred to as the Communication Constrained UAV Routing Problem (CCURP). To solve the CCURP, shortest paths between targets are computed by means of a graph transformation. Given the shortest paths between targets, two solution methods are presented. The first is a 15/2-approximation algorithm. The second method poses the CCURP as an one-in-a-set Traveling Salesman Problem (TSP), which can then be solved using known methods by transforming the problem into a regular asymmetric TSP. Computational results corroborating the performance bounds in this article are also presented.