Planning Paths for UAVs to Collect Data from Disconnected Sensor Networks

Abstract

In case of energy depletion at some nodes, a sensor network may become disconnected, and data from live nodes may not be sent to the sink. This problem can be solved by a UAV acting as a mobile data collector. However, the traditional approach is to treat live sensor nodes as independent data sources. In this paper, we consider a cooperative approach where live sensors form sub-networks, instead of acting indepen-dently. Sensors within a subnetwork can send data to each other. A UAV only needs to visit subnetworks, instead of individual sensor nodes, to collect data. We formulate the problem and propose an iterative optimization algorithm to find the shortest data collection trajectory. Given any trajectory, our algorithm iteratively merges nodes within the same subnetwork and adjusts hovering locations to minimize trajectory length. Simulations show that, compared with the traditional TSP formulation, our approach can significantly reduces the length of the trajectory.