7/24/031 ben blazey industrial vision systems for the extruder
Post on 21-Dec-2015
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TRANSCRIPT
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Introduction• The vision system rapidly analyzes the image. For
example, it might find where the item is located in the field of view, and check the tolerance of its critical dimensions. When the required computation is complete, the inspection result is then communicate to other equipment suck as a PLC (a Programmable Logic Controller commonly used to control industrial machinery). Alternatively the data is stored for future analysis.
• This process is repeated for each item as the new item moves into position in front of the camera. Unlike manual inspection, the vision system always applies the same rules objectively, and never tires at doing its programmed task.
• There are online and offline vision systems, we are interested exclusively in online systems.
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Operational Steps
1. Image acquisition: Images containing the required information are acquired in digital form through a CCD camera.
2. Image processing: After acquisition, images are filtered and restored, if necessary. Noise and unwanted reflections are removed, distortions caused by the acquisition system are also removed.
3. Feature extraction: A set of know features are extracted from the image. These features include size, position, contour measurement, and textures. The features can then be computed and analyzed by statistical techniques. The set of computed features forms the description of the input image.
4. Decision Making: The feature set is further reduced, and processed in order to reach a decision. The decision, as well as the features and measurements computed, depends on the application.
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Extruder
Extrusion Line Alternate position of IVS between vac. chamber
and cooling tank
Proposed position of IVS between cooling tank and puller. Feedback would follow, likely as a marking system.
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Vendors
Cognex – In phone contact with sales representative, currently the best option. $5000 for hardware, $2000 for software. Original Software is NT based.
Vision Engineering – Products appear to be oriented towards manual inspection. No further action taken.
Keyence – In Email contact with sales representative, they appear to have applicable hardware. Awaiting price quote. Similar system to Cognex.
Vision Controls – Hardware would be effective, price quote has been requested. System seems to be designed for a higher level of quality detection than is necessary, therefore cost may be much higher than the other companies
FSI Machine Vision – System would be effective. No price quote as of yet. A sample was sent to the companies lab in order to create a possible solution and price quote. Not sure as to an estimated cost.
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Available Components in an Industrial Vision System
1. CCD Camera
2. Software
3. Interface to PC
4. System PC
Example CCD
Dalsa CA-D8-0512W
Resolution (array size)
512 x 512
On – Chip Processing
No
Consumption 6.750W
Pixel Size 10um
Dynamic Range
54dB
Data Bits 8
Data Rate 25 MHz
Full Frame Rate
77 fps (max)
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Company Workable Specifics Cost
Cognex Yes 640 x 480 pixels
6mm element
30 fps
$7000 1,2,3
Vision Engineering
Probably not
Large Manual Camera (offline)
Keyence Probably 500 x 480 pixels
5mm element
60 fps
Awaiting quote 1,2,3
Vision Controls
Yes Single integrated unit
May be Prohibitive 1,2,3,4
FSI Machine Vision
Yes unknown Awaiting quote 1,2,3
Industrial Vision Systems
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Explanation and Significance of Frame Rates
Kg/hr 50kg 94kg
ft/min 11.2 ft 22.3 ft
In any setup the image captured will be approximately 4cm on the plane of the scintillator (2cm for scintillator, 1cm on either side)
Each image captures approximately 4cm of scintillator. The current capability of the extruder is 33.3 ft/min, which converts to ~17cm/sec. This necessitates a frame rate of at least 4fps, well within the capabilities of the CCDs being considered.
In this case, the limiting factor is the PC operating the applicable software. Given that we are currently only looking to monitor the width of the scintillator, this should not be a problem, but if the program is also analyzing corners, bubbles, color under UV light, etc it could potentially be an issue.
Extruder Production Rates
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Summary
• It remains to get price quotes from Keyence, FSI, and Vision Controls. These have been requested, and a final decision should be based mostly on these price estimates.
• Cognex, Keyence, and FSI are the best candidates.
• Current Estimate for system~$7,000 (B&W). A color system would be closer to $10,000
• Work in progress.