A VEGETABLE-PICKING robot is the latest in new technology developed by the University of Cambridge which demonstrates the expansion of robotics in agriculture.

The ‘Vegebot’ was initially trained to recognise and harvest iceberg lettuce in a lab setting and has now been successfully tested in a variety of field conditions.

The prototype still lacks the efficiency and speed of a human worker, however it goes a long way in proving that the use of robotics in agriculture might be expanded.

Crops like iceberg lettuce are particularly challenging to harvest mechanically - they grow relatively flat to the ground and can be easily damaged in the process.

“Every field is different, every lettuce is different,” said co-author of the journal of field robotics, Simon Birrell from Cambridge’s Department of Engineering. “But if we can make a robotic harvester work with iceberg lettuce, we could also make it work with many other crops.”

“At the moment, harvesting is the only part of the lettuce life cycle that is done manually, and it’s very physically demanding,” added co-author Julia Cai.

The Vegebot has two main components: a computer vision system and a cutting system. The overhead camera on the Vegebot takes an image of the lettuce field and first identifies all the lettuces in the image, and then for each lettuce, classifies whether it should be harvested or not. A lettuce might be rejected because it’s not yet mature, or it might have a disease that could spread to other lettuces in the harvest.

A second camera on the Vegebot is positioned near the cutting blade and helps ensure a smooth cut. The researchers were also able to adjust the pressure in the robot’s gripping arm so that it held the lettuce firmly enough not to drop it, but not so firm as to crush it. The force of the grip can be adjusted for other crops.

It is hoped that in the future robotic harvesters could help address problems with labour shortages in agriculture, and could also help reduce food waste.

Currently, each field is typically harvested once, and any unripe vegetables or fruits are discarded.

However, a robotic harvester could be trained to pick only ripe vegetables, and since it could harvest around the clock, it could perform multiple passes on the same field, returning at a later date to harvest the vegetables that were unripe during previous passes.