DAEE: Distributed Adaptive Exploration and Exploitation for Orientation Adjustment in Magnetic Wireless Power Transfer System

Magnetic resonant coupling (MRC) enabled wireless power transfer (WPT) systems have shown significant promise in efficiently charging multiple devices simultaneously through beamforming technology. The existing works propose various mechanisms for achieving better charging performance, but they still lack exploration of transmitter (TX) coil orientation adjustment and rarely consider the dynamic deployment of TXs. In this work, we propose the D istributed A daptive E xploration and E xploitation ( DAEE ) algorithm for orientation adjustment in MRC-WPT systems, which includes both hardware and software innovations. The hardware component features a servo motor-based mechanical device that adjusts the TX coil orientation. In the software aspect, we decompose the charging performance optimization problem and devise a distributed orientation control algorithm combining exploration and exploitation mechanisms. We develop a system prototype for the DAEE algorithm and conduct extensive experiments to validate its performance. Specifically, the TX orientation adjustment significantly enhances performance, achieving an average 103% improvement in power-delivered-to-load (PDL) compared to state-of-the-art frequency adjustment-based solutions that do not adjust orientation. Additionally, the combination of exploration and exploitation strategies in the DAEE algorithm proves effective, delivering a 24% performance improvement over the random beamforming (RB)-based exploration method.