A Multichannel Wireless UAV Charging System With Compact Receivers for Improving Transmission Stability and Capacity

This article presents a multichannel wireless rotary-wing unmanned aerial vehicle (UAV) charging system with compact receivers for improving transmission stability and capacity. The multichannel scheme and associated landing structure are proposed according to the application challenges. It contains multiple null-cross-coupled transmission paths to improve charging capability, and the structure stabilizes the charging. Compact and shielding-free receivers are embedded to avoid affecting the airflow and the weight of the flight. Misalignment-tolerant unipolar coils are designed based on transmission and field characteristics, which cooperate with the scheme for efficient coupling and restrained leakage flux. The output characteristics of the multichannel system are analyzed based on theoretical modeling and simulation. A multichannel output estimation control strategy is implemented, based on the deduced mapping relations and transmitter-side information, to regulate output currents and eliminate circulating currents. It is realized without real-time massive communication or measuring on board, and the parallel channels avoid influences of faulty channels. A multichannel experimental prototype is established and tested to prove the feasibility of the design, which can be applied to rotary-wing UAV autonomous charging flexibly.