Researchers recently published a paper in Intelligent and Converged Networks detailing a method to determine optimal positions for unmanned aerial vehicles (UAVs) in order to establish line-of-sight links with two ground users. The current UAV technology heavily relies on line-of-sight connections, which can be hindered in urban areas due to obstacles like buildings and vegetation.
The study, conducted by Yuanshuai Zheng from the Chinese University of Hong Kong, Shenzhen, aimed to address this issue by developing an algorithm to find the near-optimal UAV position. The researchers utilized a two-stage search algorithm and real 3D city maps to calculate the best placement. Factors such as building coverage ratio, which quantifies the density of structures in the area, were taken into account to simulate real-world challenges faced by UAVs.
Unlike radio frequency signals that can penetrate obstacles to some extent, free-space optical communications used in UAVs are easily blocked. The proposed algorithm ensures line-of-sight conditions by identifying the equipotential surface between two users and determining the optimal position on an approximated vertical plane. The algorithm proved effective in scenarios with obstructed views between users, achieving a performance level comparable to exhaustive 3D searches.
Moving forward, the researchers plan to investigate the algorithm’s capabilities when applied to more than two users. They aim to develop additional calculations to accommodate multiple users and work towards an ultra-low complexity online UAV deployment scheme. The ultimate goal is to create a scheme that guarantees performance while allowing rapid response and deployment in complex and changing environments.
By addressing the challenges of establishing line-of-sight links in UAV technology, this research opens up possibilities for various applications, including aerial photography, environmental monitoring, military operations, and law enforcement.
Source: Tsinghua University Press