US 11,909,228 B2
Foreign object detection method and apparatus, and wireless charging system
Chunsen Tang, Chongqing (CN); Zhihui Wang, Chongqing (CN); Yaoyi Wang, Chongqing (CN); Pengfei Bai, Chongqing (CN); Zhenzhen Wang, Chongqing (CN); Jiakai Cao, Chongqing (CN); Wei Kuang, Chongqing (CN); and Zhixian Wu, Dongguan (CN)
Assigned to HUAWEI TECHNOLOGIES CO., LTD., Guangdong (CN)
Filed by HUAWEI TECHNOLOGIES CO., LTD., Guangdong (CN)
Filed on Jun. 27, 2022, as Appl. No. 17/850,325.
Claims priority of application No. 202110721532.4 (CN), filed on Jun. 28, 2021.
Prior Publication US 2022/0416586 A1, Dec. 29, 2022
Int. Cl. H02J 50/60 (2016.01); H02J 50/10 (2016.01); B60L 53/124 (2019.01); H02J 50/00 (2016.01)
CPC H02J 50/60 (2016.02) [B60L 53/124 (2019.02); H02J 50/005 (2020.01); H02J 50/10 (2016.02)] 22 Claims
OG exemplary drawing
 
1. A foreign object detection method performed by a wireless charging system, comprising:
obtaining an induction signal generated by each detection coil in each of at least one coil group of a coil array of a foreign object detection circuit of a foreign object detection apparatus, wherein each coil group comprises four detection coils separately wound into a rectangle shape, wherein the detection coils in the coil array are arranged in a matrix with even quantities of rows and columns, wherein four detection coils in the coil array symmetrical to each other are located in one coil group, wherein the coil array is divided into four quadrants based on a row center line and a column center line of the coil array, wherein detection coils in a same quadrant have a same wiring structure wound clockwise or counterclockwise, and wiring structures of the detection coils in adjacent quadrants are symmetrical to each other relative to a center line between the adjacent quadrants;
determining an abnormal-value threshold of each coil group based on induction signals of each coil group and obtained in a first time period which is a preset time period after the induction signals start to be obtained; and
detecting, based on the abnormal-value threshold and the induction signals of each coil group, whether there is a foreign object in a detection region corresponding to the coil array.