Coordinated Air-Ground Vehicle Routing with Timing Constraints

We consider a coordinated routing problem involving an aerial and a ground vehicle for surveillance and reconnaissance mission. We are given a set of targets from which data has to be collected using a capacity-constrained aerial vehicle i.e., the aerial vehicle can hold data collected from at most a pre-specified number of targets. The aerial vehicle has to periodically upload the collected data to the ground vehicle by performing a rendezvous with the ground vehicle. This rendezvous can serve other additional purposes like recharging etc. The ground vehicle is assumed to travel with a nominal speed and the aerial vehicle is assumed to have a nominal speed range. This paper aims to compute a feasible path for the aerial vehicle that visits all the targets, identify rendezvous points for the two vehicles, compute a path for the ground vehicle through the rendezvous points so that the total travel cost of both the vehicles is a minimum. A novel technique to enforce constraints that model a feasible rendezvous for both the vehicles using their respective speed ranges is proposed. A variable neighborhood search algorithm is developed to compute near optimal paths for both the vehicles that satisfy these constraints. Finally, computational experiments that corroborate the effectiveness of the proposed algorithm are also presented.