Vegebot harvests ripe lettuce using machine vision

Iceberg lettuce has largely proved resistant to mechanical harvesting due to its fragility and its proximity to the ground. The physically demanding work is still mostly done by hand, requiring pickers to get low to the soil to clip the lettuce heads from beneath. Although Vegebot cannot harvest lettuces as quickly as humans, it could help pave the way for automated picking of leafy vegetables that are currently labour intensive.

"For a human, the entire process takes a couple of seconds, but it's a really challenging problem for a robot," said Josie Hughes, co-author of the study, which appears in The Journal of Field Robotics.

The Cambridge robot first uses an overhead camera and computer vision to capture and assess the lettuces in view. It decides whether each lettuce should be harvested based on machine learning algorithms trained on thousands of heads of lettuce in a variety of weather conditions. Individual crops might be rejected for not being ripe or carrying a disease.