Foreign Object Detection in Wireless Charging of Electric Vehicles Using Integrated Dual-Modality Sensor Array

Effective solution of foreign object detection (FOD) in the charging area is crucial for ensuring safety and efficiency in wireless charging for electric vehicles (EVs). An integrated planar electromagnetic/electrical capacitance dual-modality sensor array is proposed, which can simultaneously detect metal objects (MOs) and living objects (LOs). First, based on finite element simulation and theoretical analysis, an integrated planar coil array with nonuniform trace width is established as the dual-modality sensor, enabling both electromagnetic and electrical capacitance detection capabilities in a single sensor. Then, a dual-modality measurement system is designed that can achieve four different operating statuses, and the conductivity and permittivity distributions of the charging area are reconstructed by electromagnetic and electrical capacitance imaging. Finally, the postprocessing is performed on reconstructed images to obtain the information of the contour and location of foreign objects (FOs). In the presence of both MOs and LOs, the average intersection over union of the reconstructed images is 0.61, the average correlation coefficient (CC) is 0.79, and the average location error (LE) is 4.60 mm. These results indicate that the proposed method provides a reliable and cost-effective solution for the FOD in wireless EV charging.