Scientist develop first lettuce-picking robot New prototype could herald a new generation of AI harvesting robots

A new generation of sophisticated vegetable-picking robots guided by artificial intelligence is on the horizon after a scientists developed a prototype ‘vegebot’ that is able to pick tricky-to-harvest iceberg lettuces.

The prototype is currently five times as slow at picking the lettuces than humans- but the researchers are confident that before long the machine will have caught up.

Once that happens they hope to commercialise it for use by farmers, initially for iceberg lettuces and later for other difficult crops such as cauliflower, broccoli and celery.

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Potatoes much easier to pick

Crops such as potatoes and wheat have been harvested mechanically on a large scale for decades, but many other crops have to date resisted automation, most significantly the iceberg lettuce.

Although it is the most common type of lettuce grown in the UK, iceberg is easily damaged and grows relatively flat to the ground, presenting a challenge for robotic harvesters.

“Every field is different, every lettuce is different,” said Simon Birrell, of the University of Cambridge.

“Every field is different, every lettuce is different,” Simon Birrell

“If we can make a robotic harvester work with iceberg lettuce, we could also make it work with many other crops.”

The vegebot uses machine learning to identify and harvest the crop.

It was initially trained to recognise and harvest iceberg lettuce in a lab setting before being tested in a variety of field conditions.

Identify the target

The Vegebot first identifies the ‘target’ crop within its field of vision, then determines whether a particular lettuce is healthy and ready to be harvested.

Finally, it cuts the lettuce from the rest of the plant without crushing it so that it is ‘supermarket ready’.

“For a human, the entire process takes a couple of seconds, but it’s a really challenging problem for a robot,” said Josie Hughes, also of Cambridge University.

How it works

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.

Artificial intelligence

The researchers developed and trained a machine learning algorithm on example images of lettuces. Once the Vegebot could recognise healthy lettuces in the lab, it was then trained in the field, in a variety of weather conditions, on thousands of real lettuces.

The study is published in The Journal of Field Robotics.