Multi-Degree of Freedom Accurate Offset Angle Measurement for Coils Based on 3D Electronic Compasses

Abstract

The prerequisite for adjusting the transmitting and receiving coils to alignment is the accurate coil offset angle measurement. There is still a gap and lack of specific research on angle offset. Meanwhile, current technology is acquired in a two-dimensional (2D) plane while the inclination angle is rarely considered. This paper proposes a multi-degree of freedom accurate offset angle measurement based on three-dimensional (3D) electronic compasses. In addition, to obtain the offset angle which contains the direction, a method based on vector dot product and cross product is proposed. In addition, this paper analyzes, models and corrects the different errors to improve further accuracy. Finally, the experimental prototype is built and the results reveal that the proposed strategy can successfully complete the accurate offset angle measurement with an error of less than 1° under the 3D freedom condition of ±60° inclination angle, even if the two coils have the translational offset at the same time.