Metal foreign body detection based on double/multiple differential coils pair magnetic module

Abstract

The DDP/MDP (Dual Differential coil Pair/ Multiple Differential coil Pair) module are designed, and a multi-channel detection method for metal foreign bodies is defined based on DDP/MDP module. The DDP/MDP module structure is optimized and designed by loose mathematical modeling and multi-physics electromagnetic simulation according to the BX/Y/Z. A multi-channel detection platform is built based on the 16-bit MDP module composed of 4-bit UQV-DDP modules. Given the standard metal foreign body detection test, the system reaches the optimal metal foreign body detection state, in which the detection area is reduced by 3/4, and the parameter uncertainty is reduced to 0.5%-1.5%, responding to overall the module width range of 60–100 mm, the radius of 150 mm, and the diagonal distance of 200 mm, respectively. By comparative analysis, the accuracy of the multi-channel detection method is 3.0%, and the initial detection value is 5.0 V based on the MDP module. In comparison, the detection accuracy of the multi-channel detection method is 5.0%, and the initial detection value is 3.5 V based on the DDP module. Taking use of 16-bit MDP/DDP module detection platform, the detection accuracy of 3.0% and the initial detection value of 3.5 V can be achieved by the multi-channel detection method based on DDP/MDP module.