Farms are challenging environments for robots, and modifications to the way we grow or acceptance of a degree of human interaction "is required for the near future", robotics expert Avital Bechar of Israel's Institute of Agricultural Engineering (IAE) told a symposium at the Sival trade show in Angers, France, on 17 January.
"More efficient agricultural practices and better decision-making are required," he said. "The unstructured environments of farms mean inherent uncertainty, which makes it difficult for robots, and the same goes for crops themselves. The coefficient of variation is low for most products like nuts and bolts but is an order of magnitude bigger for, say, flower cuttings. Low cost is also required, so you use as cheap components as possible."
Many robotic tasks have been demonstrated but have not made the transition to commercial use. "The Pareto principle applies - roughly 80% of the task is easy to adapt to robots and automation, and 20% is difficult." He proposed a matrix for considering how readily a task can be automated with three levels of difficulty depending on the degree of crop-robot interaction. Bechar and colleagues are also working on a robotic system to detect powdery mildew and tomato spotted wilt virus in glasshouse peppers.
Problems yet to be solved
Michel Berducat, deputy research director of France's National Research Institute of Science & Technology for Environment & Agriculture (IRSTEA), agreed that there remain several outstanding problems to solve.
On the EU's four-year CROPS project, which investigated the viability of automated picking of apples and pears, he said: "Even with large resources it is still only at the lab phase. It's a slow process. The fruit are not easy to detect, far less pick and collect. We have robots for picking and packing chocolates but with apples it's a lot more complex. There is still a lot of work to be done. Beware of those who say they will market a picking robot tomorrow."
But adopting Bechar's three-tier scheme, some first-tier robots are already at the early commercial stage, he said, such as the TED inter-vine weeding robot from Naio Technologies. This has been the result of a partnership with a wine grower and a research centre, said its commercial director Matthias Carriere. "Could it also thin and prune the vines? We want it to be as versatile as possible. But they have to cope with a cold, wet environment. Sometimes they veer off course or fall over."
Naio's Oz, meanwhile, is a self-steering vegetable robot that can operate at different levels of autonomy. "We have around 50 of them now operating on different farms, cutting weeding time," said Carriere. The GPS-guided Dino, which took silver in the machinery and automation category of the Sival Innovation awards, straddles rows of vegetables, weeding up to five simultaneously, and at 4-5kmh can cover 4-5ha per day. "Three prototypes are being tested," he added.
"We can help with repetitive or dangerous tasks, increase productivity and quality, and reduce inputs. More growers complain that it's hard to find workers, even in wine growing and when the wages are fair."
Deepfield Robotics, part of German engineering firm Bosch, is developing a "4D" weeder that models its environment over time as well as space, according to engineer Maurice Gohlke. BoniRob uses multi- spectral cameras to locate and model weeds, and detect which are in fact sugar beet seedlings. The weeds are zapped by an electrical charge "but this couldn't work at a big scale because it's too slow", Gohle admitted. "And if you leave it too late, it's hard to tell the two apart as they start to overlap."
Semi-automated tool carrier
Claes Jaeger, scientific director of Denmark's AgroIntelli, said of its semi-automated tool carrier for field tasks, currently being developed: "We see its main use in mechanical weeding, spraying and mowing. It will become normal to see those on farms in three or four years. Right now we are not as far down in cost as we would like to be. But the biggest problem is making robots legal so they can drive to field safely without people."
Nantes-based engineering firm Sitia is leading attempts to develop PUMAgri, a multipurpose autonomous agricultural platform, with the aim of having 500 in the field by 2023. Head of robotics and innovation Sebastien Rubrecht said: "Their economic viability is a question of fixed and variable costs. Small robots don't cause too much damage, but the more equipment you embed (on a single platform), the more load it has to bear."
Mechanisation was a key theme of the 31st Sival show, which featured more than 600 exhibitors from across production horticulture and drew an estimated 22,000 visitors on 17-19 January.
Angers - Making fresh produce a priority in the city and surrounding region
The Loire Valley has made fresh produce a strategic priority. The industry is centred on the city of Angers, described by its mayor Christophe Bachut at the Sival show as "la capitale du vegetale".
The city and the surrounding region of Anjou houses more than 4,000 horticultural businesses, ranging from seeds to cider, employing some 30,000 workers.
The industry is supported by an extensive and well-funded network of training and research facilities, with some 500 researchers active in the area, while student numbers have risen by 30% in 10 years.
Angers is also home to the EU's Plant Variety Office as well as a division of France's National Institute of Agricultural Research, which includes France's official seed testing station.
Since 2011 Angers has also housed the Eden Project-style Terra Botanica theme park. It is intended to drive plant-based tourism but has struggled financially, leading to a more child-friendly revamp last year.
The city will host the World Horticultural Congress in 2022.