Circular Trajectory Planning for Localization Using Energy-Limited UAV

Unmanned aerial vehicles (UAVs) possess the potential to effectively locate missing individuals in distress scenarios by leveraging their wireless communication and flight capabilities. In the multilateration method using wireless signals, the localization accuracy increases as the number of measurements increases. However, since UAVs have limited battery capacity, it becomes imperative to optimize the UAV's trajectory within a given search region. In this paper, we propose a circular trajectory for energy-limited UAV and provide an analysis on energy consumption and localization accuracy of the circular trajectory. Based on our analysis, optimized circular trajectory can be derived in closed-form according to the search region. The proposed method not only can achieve higher localization accuracy and energy efficiency, but also allows easier rescue planning in advance. Numerical results demonstrate that the proposed method achieves superior localization accuracy compared to the conventional waypoint-based method, particularly when the energy capacity is limited.