Stabilization of Power Receiving Coil Voltage by Feedback on Wireless Power Transfer to Small Mobile Robot

Abstract

　In this study, we control the received voltage via wireless communication in the wireless power transfer applied to a small mobile robot. We developed the robot powered by 85 kHz band wireless power transfer system via coupled magnetic resonance. However, the received voltage fluctuated when the robot moves or the electronic load changes during power supply. In this case, converters are generally used on the secondary side to control the received voltage. However, in the case of the small robot, they cannot be mounted due to the limitation of weight and installation space. Therefore, we apply wireless communication to control the received voltage with a DC-DC converter of primary side. From the experiment results, the proposed wireless feedback method improves the voltage fluctuations caused by the movement of the robot by 0.5 V or less. For electric load fluctuation, the relationship between the delay time and the voltage fluctuation is evaluated.