Despite the challenges robots in an indoor climate optimised for plant and fruit growth face, Priva managed to develop the world’s first fully autonomous leaf-cutting robot.
Priva, the Dutch horticultural innovator, developed the first fully automated leaf-cutting robot for tomato crops and it’s called Kompano. This robot is one of the first mobile robots the company aims to introduce based on its autonomous platform. The developments are done through a merger of Priva and Belgian robotics innovator Octinion.
So far, Priva has concentrated on developing the Kompano leaf-cutting robot for tomato cultivation. Whereas Octinion has developed a strawberry picking robot and a UV-C robot to tackle diseases in greenhouses.
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When pronouncing the word Kompano, it nears the pronunciation of the word companion. In fact, Kompano means companion in Esperanto and indeed, the robot is designed to work in greenhouses alongside its human co-workers.
The robot is developed for greenhouse systems growing tomatoes in high wire cultivation. This means that the plant grows in a gutter system and that it is supported by wires attached to the greenhouse roof. In between the plants there’s a concrete path with tube rails comparable to railroads. The distance between the rails is standardised and so is the length of the paths and rails. Each path has a unique number and two metres from the beginning and end of each path, there’s a unique barcode. By scanning these barcodes, the robot knows it’s approaching the end of a path and that is has to turn two metres further.
Because of all the standardisations, the path numbers and the bar codes, the robot doesn’t use nor require a specialised navigation system based on GNSS, LiDAR or cameras. It transfers autonomously from one path to another and uses time of flight sensors to exactly locate the rails of the next path. The robot has front wheels that can turn 90 degrees, similar to those of a shopping cart.
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Setting the Kompano is quite easy. The only thing you need to do is to tell it whether to start cutting leaves to the left or to the right. It will then only cut the leaves in the paths on the left or right side of the driving direction. The second and last setting is the band width within it should cut the leaves. For instance between 1.1 and 1.7 m high. And you can set a return to point for when the batteries of the robot require charging. If you operate multiple Kompano units, which is to be quite common according to Priva, then each unit typically has its own charging station.
Kompano is equipped with a stereo camera that takes a photo of each plant with a depth accuracy of 1 mm. That photo is analysed and classified to determine where the lowest leaf/petiole of the tomato plant is located. This is the leaf that needs to be cut off on a weekly basis. This information is used to control and steer the so-called end-effector at the end of the robotic arm.
The patented end-effector has two fixed fingers, each equipped with twisted rollers that grab the petiole. The bladed rollers cut the lowest leaf/petiole after which the robotic hand is lowered and then it turns in such a way that the leaf falls onto the ground. The smoothness of each cut has to be flawless to prevent weak spots/wounds for infections via the cutting surface.
For the same reason, the roller knives are automatically disinfected at a desired interval by an UV-C lamp in the head of the robot. The number of cuts is counted and every 7 to 7.5 seconds, a cut occurs. After 10,000 to 15,000 cuts the roller knives need to be replaced. Removing and transporting the cut off leaves is not part of the robotic operation.
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Because of the standardised growing conditions and system, each department is about 4 hectares in size. Each hectare has 70 paths that need to be treated once a week. The robot needs 2 hours to treat each path and Priva counts on 20 hours of operability for a robot, plus 2 hours charging and 2 hours for starting the robot, to maintain it, et cetera. This way, each robot can treat 10 paths per day. The weekly range of the system should be close to 0.8 hectares to meet the performance requirements of the grower.
Priva says the challenges of the Kompano and working with it are similar to those of working with milking robots on dairy farms. But there’s also a difference: if you require 10 leaf-cutting robots, you’d most likely operate 11 with the 11th as a redundant or backup unit.
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Priva says growers have been interested in business cases and solutions to solve labour challenges in greenhouses for over 20 years. In 2001 there was the so-called Prigrow consortium in which over 70 growers and Priva participated to develop automated solutions. Lack of affordable technology proved to be the biggest bottleneck until a few years ago. Priva then challenged itself to develop robotic solutions for particular tasks, particular jobs that are very labour intensive yet don’t need to be fully automated. Tasks that are technically the least challenging and have opportunities for further automation such as robotic harvesting. Automatic deleafing was considered as such and that currently offers a 60 to 85% success rate. Other leaves are not recognised or are too hard to reach for the robotic arm.
Although the company doesn’t disclose any pricing details, it says Kompano is already competitive with human cutting based on an average wage of € 17.50 per hour. The first batch of 50 Kompano robots has been produced and sold already.