Grading fruit by size, colour and surface defects
Fruit travels in single file on a roller line and is imaged in colour from several angles while it rotates under a dome light. Diameter, colour coverage and surface blemishes are measured, and each fruit is routed to the outlet of its grade.
The grade of every fruit is sent to the line PLC, which opens the gate when the fruit reaches its outlet. The grade distribution and the rejected quantity are tracked on the operator display.
- 01 Infeed
- 02 Acquire
- 03 Analyse
- 04 Grade
Fruit arrives at the station in single file on the roller line.
- Diameter
- —
- Colour coverage
- —
- Blemish area
- —
Scenes are illustrative simulations; they are not customer references or performance guarantees.
Need
Fruit is round and a single view shows less than half of its surface, so a blemish can stay on the far side. Skin glare and the stem cavity can look like blemishes, and size and colour vary naturally from fruit to fruit.
Solution approach
Rollers turn the fruit about its own axis under the camera, while the dome gives diffuse light that leaves no glare on the skin. The successive colour images are merged into one unwrapped view; diameter comes from the silhouette, colour coverage and blemish area from the whole unwrap.
Process steps
- 01
Infeed
Fruit arrives at the station in single file on the roller line.
- 02
Acquire
Four colour images are taken while the fruit rotates under the dome light.
- 03
Analyse
The images are merged into an unwrap; diameter, colour and blemish area are measured.
- 04
Grade
The fruit is assigned to its grade and the matching outlet gate opens.
Related applications
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