Figures (15)  Tables (3)

    • Figure 1. 

      The simulation model of the electromagnetic coupling mechanism: (a) in the absence of foreign objects, (b) in the presence of foreign objects.

    • Figure 2. 

      Magnetic field intensity of the receiving coil: (a) in the state without foreign objects, (b) in the state with foreign objects.

    • Figure 3. 

      Overall flowchart of metal foreign body detection implementation plan.

    • Figure 4. 

      Installation diagram of machine vision foreign object detection device.

    • Figure 5. 

      Model structure diagram: (a) YOLOv8, (b) improved YOLOv8.

    • Figure 6. 

      Equivalent circuit of LCC-S wireless power transfer system.

    • Figure 7. 

      Structure diagram of auxiliary coil: (a) without foreign object, (b) with foreign object.

    • Figure 8. 

      Structural diagram of improved auxiliary coil: (a) without foreign object, (b) with foreign object.

    • Figure 9. 

      Collaborative optimization-based foreign body detection method.

    • Figure 10. 

      Precision curve: (a) YOLOv8 model, (b) improved YOLOv8 model.

    • Figure 11. 

      Actual detection effect of screws and nuts: (a) original image, (b)YOLOv8n, (c) improved YOLOv8n.

    • Figure 12. 

      Magnetic field simulation model.

    • Figure 13. 

      Voltage fluctuation caused by foreign objects with a load of 19 Ω: (a) a 1-yuan coin, (b) a 5 cm × 7.5 cm aluminum plate.

    • Figure 14. 

      Voltage fluctuation caused by foreign objects with a load of 15 Ω: (a) a 1-yuan coin, (b) a 5 cm × 7.5 cm aluminum plate.

    • Figure 15. 

      Voltage fluctuation caused by system input voltage variation: (a) a 1-yuan coin, (b) a 5 cm × 7.5 cm aluminum plate.

    • Parameters Values
      Primary coil size (mm) 580 × 420
      Primary coil wire diameter (mm) 5
      Number of turns of primary coil 15
      Secondary coil size (mm) 320 × 320
      Secondary coil wire diameter (mm) 5
      Number of turns of secondary coil 15
      Iron material dimensions (mm) 150 × 100 × 80
      Distance between primary and secondary coils (mm) 150
      Current (A) 100

      Table 1. 

      Simulation parameters of the electromagnetic coupling mechanism.

    • Parameters Values
      UOC/(V) 100
      Initial value of system load RL/Ω 19
      LP (μH) 7
      CP (nF) 452
      C1 (nF) 91
      L3 (μH) 70
      L1 (μH) 103.5
      L2 (μH) 80
      C2 (nF) 85
      Cin (μF) 50
      M (μH) 25
      L4 (μH) 60

      Table 2. 

      System simulation circuit parameters.

    • Parameters Values
      Auxiliary coil turns 4
      Auxiliary coil wire diameter 5
      Auxiliary coil size (mm) 30 × 9
      Primary coil size (mm) 580 × 420
      Primary coil diameter (mm) 5
      Number of turns of primary coil 15
      Secondary coil size (mm) 320 × 320
      Secondary coil wire diameter (mm) 5
      Auxiliary coil turns 4
      Number of turns of secondary coil 15

      Table 3. 

      Electromagnetic simulation model parameters.