Wageningen University and Research (WUR) in the Netherlands has revealed more details about the Next Fruit 4.0 project. This involves 35 different partners working to advance the development of technological solutions for precision fruit cultivation.
Part of the project will use grippers for robotic pruning and harvesting of pears, and for pruning redcurrant bushes. Dr Jochen Hemming, senior research associate in computer vision and robotics at WUR’s Vision + Robotics programme, explained why pears and redcurrants were chosen specifically. “At the global level there’s a relatively strong focus, both scientifically and commercially, on robots for picking apples,” he said. “But the harvest period in the Netherlands is just six to eight weeks, and, in fact, more pears than apples are now grown in Benelux. As part of the cost-minimisation aspect of the project we’re looking at multifunctional applications of robots and grippers, so it makes sense to look at pruning as well as harvesting.
“A shortage of qualified workers is making it increasingly difficult to perform both those tasks. And because the participating fruit growers include redcurrant growers, the scope was broadened to the pruning of redcurrant bushes.”
He added, “Robotising secateurs isn’t the problem. We managed that pretty quickly. But detecting which branches need to be pruned is proving much more challenging than we initially thought. The obvious choice of technology for this is a stereo camera, such as the familiar and affordable Intel RealSense or StereoLabs ZED cameras. These are appropriate in terms of their cost and computing power, but they struggle when it comes to recognising thin objects such as twigs and support wires and dealing with direct sunlight and moving branches and fruits. Alternative cameras are generally too expensive in this context. Meanwhile, LiDAR sensors generate a lot of data that can’t easily be processed in real time and the data also doesn’t include information on colour, which is often essential for identifying ripe fruits or the type of wood to be pruned”.