letbot

The AHDB has unveiled a new lettuce leaf-peeling robot developed by PhD students at Cambridge University.

AHDB student Luca Scimeca was part of a team at Cambridge University helping build a specialist bot that can tear away the outer leaves of lettuce crops, normally performed manually.

But with seasonal labour in short supply, British horticulture is increasingly looking to artificial intelligence and robotics to solve a serious skills gap.

Scimeca’s new robot is currently capable of achieving full leaf removal 50 per cent of the time, with the process taking an average of 27 seconds to complete.

The creation by the team, led by Dr Fumiya Iida, lecturer in Mechatronics, of a 3D-printed circular nozzle, mounted on the end of a robotic arm and tested with a suction system, acts as the single vacuum suction point. It is designed to grab a leaf and remove it from the main body of the lettuce using a tearing action, without causing damage to the produce.

Crucial to the accuracy of the leaf tearing is the use of computer vision to locate and determine the positioning of the lettuce. It does this by first detecting the lettuce stem with the aid of a 2D web camera placed directly above and within the assumed field of vision.

Luca Scimeca, from the Biologically Inspired Robotics Laboratory (BIRL), and funded through the AHDB studentship scheme, said: “Lettuce leaf peeling is an interesting robotics problem from an engineering perspective because the leaves are soft, they tear easily and the shape of the lettuce is never a given.”

“The computer vision we have developed, which lies at the heart of our lettuce peeling robot, can be applied to many other crops, such as cauliflower, where similar information would be required for the post-processing of the produce.”