Healthy, juicy, popular: According to the Food and Agriculture Organization (FAO) of the United Nations apples are among the most popular fruits worldwide – along with bananas, citrus fruits and watermelon. But there is one challenge: a lack of harvest workers for the 4.9 million hectares of apple orchards worldwide, an area larger than Switzerland. Their owners can hardly find seasonal workers. The Corona pandemic has recently exacerbated the situation. Julian Stockschläder, Business Development Manager at KUKA, has been working on the so-called KUKA CropBot, a pilot project, since 2020 and reveals, “The automation potential is huge. For the apple harvest alone, 1.6 million robots can be used globally. That doesn’t even take into account other dessert fruit, such as pears, peaches or nectarines.”
Sucking instead of grabbing: The gentle way to harvest apples
So the potential is there, and KUKA has the innovative strength and process expertise to back it up. But apples place very special demands on their automated harvesting. Julian Stockschläder explains: “They have to be picked automatically from the tree without damage and packed into different crates – depending on the degree of ripeness, condition and size.” The ideal solution: a vision system with a vacuum suction cup. Compared to a gripper, it can distribute pressure more evenly over the surface of the apple. And cameras detect crucial parameters.
Strong partners for special challenges
Dutch systems integrator RIWO successfully developed the appropriate artificial intelligence and vision technology for the pilot project with KUKA and Wageningen University. Two cameras create a point cloud for each apple on the tree and pass the associated information to a KR AGILUS from KUKA, which sucks them in and harvests them.
The small robot is extremely maneuverable, even in the smallest of spaces. At the same time, it impresses with its speed and precision. It is also waterproof, a decisive criterion. “The KUKA CropBot is designed for outdoor use. No robot manufacturer currently offers kinematics that are suitable for this in terms of dead weight, IP protection class, number of axes, reach, lightweight construction, safety, costs and control,” Julian Stockschläder continues. So, there is potential for development here, which calls for clever solutions.
In demand: a weatherproof robot with a mobile base
This leaves one crucial question unanswered: How does the KUKA CropBot move across the orchard? Munckhof has over 137 years of experience with innovations in fruit growing and is the market leader for harvesting machines.
First harvest season successfully completed
The system passed the practical test during the 2021 harvest in the Netherlands, also thanks to the great preparatory work of the partners. Munckhof had already automated the harvesting process as far as possible – from the apple being placed on a conveyor belt, to sorting by condition, to further logistics. KUKA has closed the last gap. Currently, a team led by Julian Stockschläder is working on further details, such as the picking rate, which was last at five seconds per apple. “Our robot can theoretically pick very quickly, in the range of a few seconds,” says the Business Development Manager. “But of course the focus is on the integrity of the apple. We’re working on the ideal balance of cycle time and harvest quality.”
The future of agricultural robotics
Together with strong partners, KUKA has shown that it is possible to detect the degree of ripeness of apples directly on the plantation using a vision system, calculate their position and path planning, and remove them from the branch using a special vacuum suction cup. Among other things, the development of a prototype and the pre-market launch are on the agenda for the next few years. In the future, the system should also prune branches automatically. In addition, it is conceivable that the KUKA CropBot could be used to pollinate apple blossoms. Wageningen University is currently researching methods to automate this process. “Worldwide, there is currently no portfolio from a robot manufacturer that meets the requirements in agricultural robotics. With the KUKA CropBot, we would like to offer the first robot that is suitable for automation in agriculture,” concludes Julian Stockschläder.
