Fig. 1. Composition diagram of three-axis visual coordinate system

Fig. 2. Defocus model of optical system

Fig. 3. Intersection point picture of two curves

Fig. 4. Schematic diagram of the large difference between the focus range center point and the on-focus point

Fig. 5. Schematic diagram of image collection point range

Fig. 6. Three-axis vision coordinate measuring system

Fig. 7. Schematic diagram of gauge block

Fig. 8. Schematic diagram of the gauge block perpendicular to the optical axis of the camera

Fig. 9. Relationship curve between camera position and image sharpness

Fig. 10. Gaussian fitting curve

Fig. 11. Placement diagram of two gauge blocks

Fig. 12. Measuring the thickness of the gauge block