Abstract
This work proposes power-efficient trajectory adjustment and temporal routing algorithms for a network of unmanned aerial vehicles (UAV) that are deployed to monitor or gather data from underlying sensors in the field. Here, we consider fixed-wing UAVs that are assumed to follow circular trajectories whose radius can be adjusted to reduce power consumption while maintaining coverage over its responsible service area. Given the multihop transmission paths from the UAVs to the data-gathering node, power-efficient flight-radius adjustment strategies are proposed based on the total power minimization and lifetime maximization criteria while maintaining the existence of the paths. Then, by establishing the relationship between routing in UAV networks and that in general temporal graphs, we propose a power-efficient (PE) temporal path algorithm based on the minimization of the accumulated square of the minimum achievable powers of all UAVs on the path. Computer simulations are provided to demonstrate the effectiveness of the radius adjustment strategies in terms of both total power minimization and lifetime maximization, and the power-savings provided by the PE temporal path algorithm.