Hardware manual

Impact Reference Guide Circle Gauge
3-117 Datalogic Automation Inc.
Circle Edge Detect Type
The first three settings are designed to find one edge point per ROI. The tool will then find fit the circle with
least squared error.
The last three settings will find multiple edge points per ROI. In these cases, a least squared error fit is unre-
liable, so the tool will first do a Hough transform to find the subset of points that are within nominal diame-
ter tolerance, and then do a least squared error fit. The Hough transform step adds time, so it should only be
used when you cannot reliably find the correct single edge on the majority of the ROIs.
If there are close concentric circles, then you should set the Diameter Tolerance with limits that separate the
circles. For example, if you are finding a circle with diameter 100 and there is also a concentric circle with
diameter 110, then you should set the upper limit of the Diameter Tolerance to 105 so that the tool can dis-
criminate between them.
Circle Gauge
In the Feature Finding, Locating, and Measurement Drawers
The Circle Gauge tool radially searches for edge points within the ROI, then finds the best fit circle to the
found points. The tool can be set to find either a circle or a ring. It will output an origin placed at the circle or
ring center.
If the tool is set to find a circle, the pass or fail can be based on the average radius, as well as the percentage
of the radial lines that contain found points and that fit the radius tolerance.
If the tools is set to find a ring (two circles that make up the Inner Diameter (ID) and the Outer Diameter
(OD) of the ring), the pass or fail can be based on the fitted radius of the ID and OD; the thickness and con-
centricity of the ring; and the percentage of radial lines that contain found points on both rings and fit the
radius and ring thickness tolerances. See “How to set up the Circle Gauge tool” on page 3-120.
Bounding Circle
Diameter List
If Bounding Circle Enable is True, this is the list of Bounding Circle diam-
eters.
Input Name What it is
Input Image Linked Image
Tool Origin The tool’s origin relative to the entire image space
Circle ROI The desired region of the image to search.
Circle Type See “How to set up the Circle Gauge tool” on page 3-120
Edge Detection
Method
Gradient Edges or Grey Level Edges
Gradient detection generally provides more consistent results. In some
cases Gradient detection can pick up extra edges in a noisy image and
Grey Level detection may offer better control.
See “Edge Detection Method” on page 3-78.
Edge Detection
Sensitivity
The sensitivity level determines the transition level necessary for detec-
tion. A higher value detects more edges.
Output Name What it is