Machine Vision: End User Solutions
Flaw Detection
Flaws–such as contamination, scratches, cracks, discoloration and burn marks–are small changes in the appearance of a product that might indicate defects. Flaws are usually random, so machine vision looks for pattern changes, changes in color or texture, or for a particular type of connected structure.
DALSA Vision Appliances allow easy integration of critical components such as lighting. Surface flaws are often hard to detect, even by humans. Often they are low-contrast and random in their patterns. Proper lighting must be used to “amplify” flaws if they are to be detected by a machine vision system. In some cases multiple types of lighting are needed to show all classes of flaws.
Examples of Product Flaw Detection
Contamination on medical instrument |
Tiny contamination marks on the instrument surface are segmented from the background using high resolution DALSA cameras and diffuse illumination. DALSA surface flaw tools are able to adjust for natural discoloration of surface coatings to extract true defects. |
Process problem detected by color  |
Flaws in the manufacturing process can often be detected by color or texture change. For these applications, defective product must be differentiated from normal process variation. DALSA color tools are able to verify and detects subtle variations in color that result from changes in the manufacturing process. |
Flaw detection on textured tile  |
Connected line patterns indicate surface scratched or cracks. Machine vision differentiates these from the irregular patterns associated with good quality tiles. Defects like these can be further graded as acceptable or unacceptable according to feature characteristics such as area, length, direction and brightness. |
Use of Line Scan Cameras
Automotive Valve Inspection
Line scan cameras are commonly used to unwrap cylindrical surfaces, such as automotive parts, for inspection.
In this application many inspections are performed to ensure that the valve surface is free of cracks and that all gaskets and filters are correctly installed and defect free.
Unwrapped Image for Inspection
