Machine vision in robotic polishing
Where vision helps in polishing —part, path and finish— and where the physical sample and measurement still rule.
In polishing, vision can locate the part, correct the contact point or inspect the finish. It does not replace force control, abrasive or the reference sample. The right question is which part of the problem is visual and which is process.
What vision can do
Locate the part and orientation, detect presence, correct the starting point or inspect marks and uniformity. These are different functions: the same camera is not bought for all of them.
Finish inspection: what can be seen
Vision detects marks, scratches, missing areas and color variation under controlled lighting. Ra or gloss require specific instruments. Vision can complement, not replace, measurement.
| Criterion | What it evaluates | Limit |
|---|---|---|
| Marks and scratches | Visible defects with contrast. | Depends on lighting and angle. |
| Uniformity | Finish differences on the surface. | Does not measure Ra directly. |
| Ra / gloss | Measurement with a specific instrument. | The camera does not replace the roughness tester. |
Vision and force control
Vision can say where the part is, but not how much force to apply. Force control and path remain part of the cell. Without that combination, vision does not improve finish.
Part variation and fixturing
If the part varies, vision can correct the contact point; if fixturing does not hold it, no camera solves it. Holding remains the basis of repeatability.
When vision is not needed
When the part is always in the same position, fixturing presents it the same way or inspection uses a physical sample. In those cases vision adds complexity without improving the result.
Frequently asked questions
Does vision improve the finish?
It can locate the part and correct the contact point, but finish depends on force, abrasive, fixturing and testing. Vision alone does not guarantee it.
Can it measure Ra or gloss?
Not directly. It detects marks and uniformity under controlled lighting; Ra and gloss require specific instruments.
When is vision needed?
When part position varies or marks must be inspected repeatably. If the part is always the same, fixturing may be enough.
Does it replace the reference sample?
No. The sample still defines the finish. Vision can help compare, but the criterion is agreed with a physical part.
How does it integrate with the cell?
Vision provides position or result to the robot and PLC. It must coexist with force control, extraction and safety.
When is it not needed?
When the part is always in the same position or inspection uses a physical sample. Vision adds complexity without improving the result.
