摘要
This work proposes power-efficient trajectory adjustment and temporal routing algorithms for a network of fixed-wing unmanned aerial vehicles (UAV) deployed to gather data from underlying sensors in the field. To stay afloat, each UAV follows a circular trajectory above its responsible service area with a radius that can be adjusted to reduce its propulsion energy consumption. The data gathered by the UAVs are sent to the data-gathering node using multihop transmissions over other circulating UAVs. First, given the multihop transmission paths from all 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 connectivity over the multihop 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 total pair-wise flight power consumption among consecutive UAVs on the path. Finally, we propose an iterative procedure to refine the initial phases of the UAVs' circular trajectories to further improve the power efficiency. Computer simulations are provided to demonstrate the effectiveness of the proposed schemes in terms of both total power minimization and lifetime maximization.