Application: Presence Verification

Inspection Challenge:

A manufacturer wanted an automated system to stamp five holes on supplied labels.

Measure and Access:

• Detect if there are five holes present on the supplied labels.
• Check for the X and Y co-ordinate of each hole.

Machine Vision Solution:

The following DT Vision Foundry tools were added to the Point and Click Script to solve this inspection challenge:

• Picture Tool – This takes pictures of the product to be analyzed. These images will be live.

• Search Tool – The Search Tool locates a reference point each time an image is captured. This will be set to a given area, which has been applied by the operator.

• Position – A rectangle region of interest has been drawn around the given area. This is where the customer’s analysis will be performed. The ROI will be positioned each time a new image has been captured, using the X and Y co-ordinates of the Search Tool.

• Blob Analysis – The Blob Tool performs an analysis in the given area. The Blob Tool is looking for the five holes. The X and Y co-ordinates have been taken for each blob as well to locate the X and Y position of each hole.

The screen shot above shows that the image has been captured from a camera and displayed in a view-port. The screen shows that the Search Tool has found its reference point, which allows the user to find the most common point each time. The screen also shows that a rectangle region of interest has been drawn around the area, which is under analysis. The Position Tool positions the ROI each time an image has been captured. The ROI will follow the X and Y co-ordinates of the Search Tool, which has been set by the user. A blob analysis has then been performed on the given area. The Blob Tool is looking for the five holes and for the X and Y co-ordinates for each hole. The X and Y variables are taken from the Blob Tool. This will give the X and Y position for each of the holes. The X and Y co-ordinates are displayed in the Debug Box. A text statement has also been added to the script. This will be brought upon the screen to tell the user how many holes have been found. The Blob Tool will also export the X and Y co-ordinates to an Excel spreadsheet.

The screen shot above shows that another image has been captured through the camera and displayed in a view-port. The screen shows that the Search Tool has followed the criteria set and has found the reference point. Now that the Search Tool has found a reference point, the region of interest re-positions itself by using the X and Y co-ordinates of the search. The Blob Tool then performed an analysis on the given area. The Blob Tool found all five holes; this is displayed through the text statement. The Blob Tool has also found the X and Y co-ordinates of the five holes. This is displayed in the Debug Box. The information has then been exported to an Excel spreadsheet through the DDE transfer. This will allow the user to see the X and Y co-ordinates each time a new image has been captured.

This routine will continue checking the differing areas of the image until the user/programmer is satisfied that the job is done, and then if needed, the system can be used for checking a variety of many other products.

From then on, there are a number of scenarios that can be implemented. The I/O Tool can signal the user’s PLC to operate a robot to discard the failed articles and to let the passed articles carry on down the production line.

The I/O Tool can even make the production line stop if there is any faults found with the products that are being checked.

Result:

The feasibility study showed that the product could be analyzed by using Vision Foundry’s tools. The product should be located within the image. This will allow the Blob Tool to perform an analysis in a quicker time on the given area.