electronic imaging fundamentals: pressure die castings
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Electronic Imaging Fundamentals: Pressure Die Castings. August 2008. “..any sufficiently advanced technology is indistinguishable from magic.” Arthur C. Clark. - PowerPoint PPT PresentationTRANSCRIPT
Electronic Imaging
Fundamentals:
Pressure Die Castings
“..any sufficiently advanced technology is indistinguishable from magic.” Arthur C. Clark
August 2008
Background: Quality control is of major importance in the pressure die casting industry. Inspection of the item by human inspectors prone to short and long term variations.
An automated casting inspection system using cameras is proposed.
Requirement: Provide image analysis technology linked to a camera to measure size / thickness / angle / shape and other parameters as required.
REJECT when measurement obtained is outside SPEC, allowing casting to be rejected.
Why do Image Analysis?
Better Definition of Contrasting Areas Improved Precision/Accuracy in Measurements Reproducibility of Results Higher Throughput than Manual Methods
A Word About Our Eyes
Eyes are very good contrast adjusters, but not good for distinguishing subtle variations in color
Eyes can discern about 30 continuous levels of gray or color in a field of view
Eyes are not good judges of distance Eyes cannot accurately reproduce
measurements
Which is BIGGER / LONGER???
Electronic Imaging Fundamentals
Acquire
Process
Identify
Analyze
Report
Arguably, the most important aspect of all Proper setup of imaging apparatus is vital Obtain maximum contrast and dynamic range Reduce “noise” and other unwanted artifacts Uniform lighting (light) Product presentation (right way up) Resolution (CCTV VS DIGITAL)
Acquiring the Image
Slide 9
www.I-Cube.co.za
Lens
Image sensor Digitizing
Pre-processing
Timing Interface
PLC
Cat-5e Ethernet cable up to 100 m
Local I/Os:- Trigger input- Results output
Illumination control
Image ProcessingIn PC
Illumination
(Lens Iris Video)
Power
Acquire
Calibration
Thresholding an Image Select appropriate morphometric characteristics
Identify regions of interest to analyse
Mask regions
ColourSizeShape Intensity
DATA
Recorded Rejected
20080814_18-25- 0.514 20080814_18-25- 0.514 20080814_18-25- 0.523 20080814_18-24- 0.862 20080814_18-24- 0.504 20080814_18-24- 0.407 20080814_18-24- 0.162 20080814_18-23- 1.17 20080814_18-21- 0.281 20080814_18-21- 1.806 20080814_18-21- 0.169 20080814_18-20- 0.626 20080814_18-20- 0.969 20080814_18-19- 1.121 20080814_18-18- 0.957
NEXT STEP: Consulting @ R 7 500.00 to explore:
- CCTV vs DIGITAL (accuracy)
- Measurement process (11 measurements)
- Image setup
- Equipment required
- Input Trigger / rejection
- Image / data storage