Glossary · Machine vision
Presence check
Also known as: Presence detection, Presence verification
German: Anwesenheitsprüfung
In manufacturing and machine vision, a presence check verifies whether a specific part or feature is present at an expected position, using a camera, a sensor or a simple image processing tool, and reports a binary result.
- Machine vision
In one sentence
A presence check verifies whether a specific part or feature is at an expected position and returns a simple yes or no.
Example
A presence check confirms that the O-ring is in its groove before the valve body moves to the pressing station.
How it applies
- Engineering: Presence checks are the simplest vision task and are often done with a Smart camera or a vision sensor. Contrast between feature and background decides robustness.
- Operation: The check must fail safe for quality: a missing image or unclear result should lead to rejection, not a pass.
- Documentation: The documentation team should document which feature is checked, how a failed or unclear result is handled and how the check is tested with a part missing the feature.
Presence check vs. presence-sensing device
A quality presence check verifies parts in a product. A Presence-sensing device (PSD) in machine safety detects people in a hazard zone and is a protective device with safety ratings. The words are similar; the purposes are different.