Staging, sometimes called fixturing, holds the part to be inspected at a precise location in front of the camera for a Vision Appliance™ to 'see'. Staging is required for three reasons:
- To ensure that the surface of the part that you want to inspect is facing the camera. In some cases the 'parts' may be rotated to inspect multiple surfaces.
- To hold the part still for the brief moment required for the camera to take a picture of the part. If the part moves too much while the picture is taken, the image may blurr. In some cases the parts move so slowly that they do not need to be held still for a good picture. In other cases a 'détente' or other mechanism holds the part still for a brief moment. Generally, the motion of the part is 'frozen' by turning the light on very briefly or by using a high-speed electronic shutter, standard on the ipd recommended cameras.
- To speed up the processing by putting the part in a location known to the Vision Appliance. All machine vision systems must first search to find the part in the image, and this takes time. If you can arrange the staging to always put the part in about the same location, then the vision system 'knows' where the part is and can find it much more quickly.
Staging usually is mechanical. It also usually includes a Part-in-Place sensor that tells the machine vision system when a part is in front of the camera. This sensor is usually a simple light source and photoelectric detector, for example