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Robots take to the field

A completely autonomous equipment fleet scouts out weeds, 
creates a work plan to control them and carries it out

UAV aircraft drone

The RHEA (Robot Fleets for Highly Effective Agriculture and Forestry) display shared space with another organization in one of the smallest booths at Agritechnica last November. But the commercial possibilities in agriculture for its ground-breaking robotics project are enormous.

“We have developed a fleet of robot tractors that work together in the field,” said Constantine Valero Ubierna, professor of engineering at the Polytechnic University of Madrid. That fleet of machines seeks out weeds in a field and gets rid of them, all on its own.

The RHEA concept is a gigantic step into the future for automated farming. Creating the system took the combined efforts of a consortium of companies and funding assistance from the European Union.

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“First of all, we fly two drones, two aerial mobile units that go over the field and create a map of where the weeds are,” Valero Ubierna continued. “They create a working plan which is sent wirelessly to the tractors. Then the tractors go into the field by themselves and spray only where the weeds are.”

“AirRobot is a part of the RHEA project from Europe,” said Yves Degroote, sales manager for AirRobot, a German company that builds UAVs (unmanned aerial vehicles). “We are the partner that is developing the flying platforms,”

“Our role is we fly over the areas to define (them),” he continued. “We divide it (the field) into areas and with the cameras, we see how many weeds there are. We have multi-spectrum cameras on board. (Using) those cameras hooked up to software is how we detect weeds.”

“Although most of the (project) components are commercially available, we’ve had to modify the design or software of most of them to make them work (together)” added Valero Ubierna. “It was lots of hours of work.”

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At the start of the project, the challenge for AirRobot’s engineers was to scale up the lift capacity their relatively small UAVs.

“Our platform needed to be able to carry a certain amount of weight,” Degroote explained. “This was the biggest challenge (for us). The first units we produced were small and carried only 200 grams. These need to carry a payload of one and one half to three kilos. So we needed bigger platforms. They’re much different than the smaller units we build.”

Fitted with a GPS guidance system, the bigger UAVs fly a predetermined route to map a field. “The drone has GPS onboard and this is how we divide the whole field into sections,” he added. “It’s (flight) is pre-programmed on a map. With waypoint navigation it follows the track it’s programmed with. In this case it’s flying quite low, 30 to 40 metres. You can map multiple hectares in one flight.”

Aerial drones and driverless tractors team up to search for and destroy weeds in farm fields in the RHEA robotics prototype system.
Aerial drones and driverless tractors team up to search for and destroy weeds in farm fields in the RHEA robotics prototype system. Aerial drones and driverless tractors team up to search for and destroy weeds in farm fields in the RHEA robotics prototype system. photo: RHEA

The data collected by the UAVs is transferred to a mobile ground control station and fed into a server. Although all the data transfer and analysis takes place automatically, the ground station is designed to be staffed by a human to oversee the process.

“That data (from the UAV) is then sent to a central server,” Degroote said. “In real time you have the data from the drone at the ground station. Then there is a plan made for the tractor.”

Enabling the system to create that plan required the development of special software, which actually makes decisions about whether or not to attack weeds and how best to do it based on stored data.

There is even more analysis done by computers onboard the modified, unmanned, 47 horsepower New Holland Boomer T3050 tractors before they carryout any actions. The decisions required there depend on the type of field and weed control work the tractor is equipped to do.

Spray tractors in the program use GPS to respond to the correct location in wheat fields and then apply one of a number of onboard chemical options at the various locations.

For work in corn fields, tractors are equipped with two cameras that further analyze weed clusters. Software then decides what type of eradication action is necessary to kill them: tillage for non-selective eradication or LPG burners for selective work.

As the project nears the end of its four-year term, the RHEA team is getting ready to officially show its autonomous system to the world. It will hold a public field demonstration in May near Madrid to showcase the finished product.

“It’s a four-year project and we are in the final year” explained Valero Ubierna. “Next May will be the final demo near the Robotic Centre in Madrid. Everyone is invited to come and see the fleet working.”

That will mark the end of the development phase. From then on, what happens to the system depends on whether or not a manufacturer is interested in commercializing the concept.

“This is the first step in the development process with a lot of European partners,” said Degroote. “Now the next step is making it commercial.”

“The objective on the project was to demonstrate it’s feasible” added Valero Ubierna. “Now we (need to) get the support of a manufacturer to do it in a commercial way.”

Valero Ubierna thinks it’s viable for farmers or contractors to consider incorporating the fine-tuned autonomous system into their operation. “A medium or large-sized enterprise could do it,” he added.

So when can farmers expect to turn drones loose in their fields? “I would say easily between five and 10 years,” said Degroote. And will the price tag be low enough to allow the average farmer to take advantage of the technology? “It’s quite difficult to say at this time,” he added. “But that’s what you’re aiming for at this time, that it’s affordable for all farmers.”

About the author


Scott Garvey

Scott Garvey is a freelance writer and video producer. He is also the former machinery editor at Grainews.



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