February 18, 2016      

The Netherlands is one of the world’s largest food exporters and is rapidly emerging as a global center of expertise for the development of agricultural robotics. Innovative schemes across the country are focused on moving toward unmanned farming and horticulture.

One interesting project is seeking to further develop technology created as part of the Crops (“Clever Robots for Crops”) initiative. The EU Seventh Framework Programme (FP7) project has carried out extensive research and development for a robot to harvest sweet peppers.

The Sweeper (short for “Sweet Pepper Robot”) project aims to introduce, test, and validate a robotic harvesting system under real-world conditions — with the ultimate objective of putting first-generation greenhouse harvesting robots onto the market.

“Until now, this has never been achieved — and it will ensure Europe’s leading role in agricultural robotics,” said project coordinator Jochen Hemming, a senior researcher in computer vision and robotics in horticulture at Wageningen University and Research Centre (Wageningen UR).

As well as Wageningen UR, the international consortium includes UmeA University in Sweden, which is responsible for software development, and Proefstation voor de Groenteteelt (PSKW, or Research Station for Vegetable Association) in Belgium.

PSKW is mainly focused on the adjustment of crop morphology to facilitate robotic harvesting.

Another key partner is the Dutch systems integrator Irmato, which is focused on transforming specifically designed subsystems into “practical, useful harvesting equipment.”

If the project is successful, Irmato will probably be responsible for putting the robot on the market.

Cucumber, pepper harvesters took time to mature

Although coy about the exact details, Hemming revealed that the starting point for the new technology is the sweet pepper harvesting demonstrator robot created for the Crops project.

Wageningen UR and other European researchers have developed a pepper-picking robot.

Sweeper was developed under the Crop program. Source: Wageningen UR Greenhouse Horticulture

For Sweeper, the team will also use an industrial robotic manipulator, a Fanuc LRMate200iD, alongside colour and 3D cameras — as well as active illumination for fruit detection, ripeness determination, and obstacle avoidance.

In addition, the technology will build on other projects carried out earlier at Wageningen UR, such as an initiative focused on the robotic harvesting of cucumbers.

Although earlier experiments with the integrated pepper harvester have proven the feasibility of harvesting sweet peppers autonomously, Hemming acknowledged that harvest success was limited to “a maximum of 33 percent successfully harvested fruit.”

“The average cycle time to pick a fruit was 94 seconds,” he said. “But much more important is that we made a detailed fault analysis that now serves as input for the Sweeper robot.”

Looking ahead, Hemming added that the main challenges still facing the project team relate to how best to deal with the “unstructured environment” and the “hostile and ever-changing conditions” in the greenhouse, including humidity, high temperature, and changing lighting.

Other potential hurdles include the very limited space between the plants, the dense canopy with fruit occluded by other fruit or leaves, and the “economic feasibility of the system,” he said.

Driverless Greenbot operates at the touch of a button

Elsewhere, Dutch companies Conver BV and Precision Makers have also produced the Greenbot, the first driverless machine developed especially for professionals working in the agricultural sector who have to carry out repetitive tasks on a regular basis, such as working in fruit cultivation, horticulture, agriculture, or the municipal sector.

The Greenbot uses patented “Teach and Playback” technology to perform a wide range of activities “with no manual input whatsoever,” explained Ralf Kroonen, product manager at Copenhagen-based Precision Makers.

To program the system, users simply press the teach button to start recording a route, before the device begins driving, mowing, and spraying.

“The system stores every action, including steering, accelerating, mowing and spraying, multiple times per second,” said Kroonen.

“The system is able to store hundreds of routes,” he added. “To repeat a recorded route, simply select the appropriate route, and drive the tractor to the starting point. Press ‘Go,’ and the tractor will repeat the recorded route precisely and unmanned.”

The Greenbot has already undergone a successful testing regime at an orchard in the Netherlands, and Kroonen confirmed that the first Greenbot has now been sold to a contractor in the country’s municipal sector.

Conver is working to introduce the machine in the U.K. and other European nations, as well as the U.S.and Japan, said Tom Rosier, sales director at the company.

“The markets are unlimited — tractors are used in so many ways; we will see what markets would be finally the best,” he noted.