Research on constant current output control for wireless charging of UAVs

In the context of an increasingly intelligent and modernized society, Unmanned Aerial Vehicles (UAVs), commonly known as drones, have been extensively deployed across various sectors. Despite their broad applications, the operational longevity of UAVs is often constrained by the limitations of their onboard battery capacities, particularly during extensive and prolonged missions. Wireless power supply has emerged as an efficacious solution to this challenge, potentially extending the operational duration of UAVs. However, the wireless charging process for UAVs is subject to various influencing factors, and maintaining a constant current is essential for the long-term health and service life of the UAV's lithium batteries. This paper introduces a constant current output control scheme for the wireless charging of UAVs to mitigate these issues. The primary research focuses on initially formulating the expression for the output current, investigating the impact of mutual inductance perturbation, and various system parameters on the output current. It further delineates the conditions under which the output current remains invariant to load impedance variations. Subsequently, to counteract the perturbations in mutual inductance, the paper proposes a constant-current output control scheme predicated on the estimation of mutual inductance. Specifically, by employing an offline-trained Artificial Neural Network (ANN), the mutual inductance can be estimated solely based on the current measurements from the transmitter side. Finally, to enhance the system's responsiveness to the continuous variation in mutual inductance, a Radial Basis Function (RBF) network is employed as an alternative to the ANN, thereby improving the system's agility.