Adept AdeptSight User Guide - Manual (Page 391)

Gripper Clearance Tool
Description
The Gripper Clearance tool is a filter used to determine which parts can be picked without
interference. Instances returned as results have passed the filter.
The tool uses histograms (typically one histogram per gripper finger) to determine whether
the gripper can pick up a part without interference from another part or edges of the region of
interest (ROI). Each set of histograms is applied to each instance in the region of interest.
You use the Inspection Configuration field to specify the maximum and minimum Grey Level
Mean, Variance, or Histogram pixel count, which are applied to all histograms in the tool. All
histograms for an instance must have a value between the maximum and minimum, inclu-
sive, for that instance to pass the filter.
l Grey Level Mean - This is absolute greylevel, and will change with lighting and other
environmental changes. For this reason, it is best-suited for situations where these
conditions will be constant (a clean, homogenous background and constant lighting
intensity).
l
Variance - This is the difference, from the mean, of the greylevel values in the his-
togram. Because it is relative, it is useful when lighting and other conditions may
change.
l Histogram pixel count - This specifies the number of pixels, in each histogram, that
may fall in the greylevel range that you specify.
To create a Gripper Clearance tool, right-click in the Tree structure, then select:
New > Vision > Tool > Gripper Clearance
All histograms are rectangles. Each histogram can be sized, rotated, and moved as needed, to
mimic the size and position of the gripper fingers. Editing can be done by modifying Offset and
Search Region in the configuration section, or with the mouse in the display window.
Gripper Clearance Tool
AdeptSight User's Guide, Version 3.2.x, Updated: 8/23/2012
Page 391