Increased precision of data gathering to guide inputs could offer value for arable farms. Jane Carley finds out what role robotics could play in this.
The Small Robot Company has taken further steps towards final production of its autonomous farm machinery range. The commercial specification version of its ‘Tom’ monitoring robot was recently unveiled at the Lockerley Estate, Hampshire, where farm manager Craig Livingstone, a member of the company’s farmer steering group, hopes to use robotics to help with management decisions.
This version of Tom has been manufactured in Blythe, Northumberland, by Tharsus, a machine and robot designer and manufacturer which also makes Ocado’s warehouse robots. A development of SRC’s previous prototypes, Tom has a six-metre boom which mounts six cameras to scan the field or crop. Compared to previous incarnations, it features a more robust and substantial design while exerting ground pressure said to be less than that of a human. Four-wheel steer offers manoeuvrability within the crop.
Tom is now operational in-field at three farms including Lockerley and is said to be capable of covering 20 hectares per day autonomously, collecting about six terabytes of data in an eight-hour shift, detecting millions of data points per field.
As an example, Tom collected 12.7 million plants in a single 6ha field, of which 250,000 were identified as weeds.
Plant details can be distinguished at submillimetre resolution and the next generation Tom also incorporates increased speed, 5K camera capacity and extended battery life. It can also generate sensor data such as soil health and even biodiversity from recording birdsong, says its creators.
When used to inform weeding, data stored on an SSD card is uploaded to the cloud and used by the artificial intelligence platform Wilma to identify and map the individual weeds, devising a weed treatment plan.
Tom’s design will also form the basis for the final prototype of the ‘Dick’ weeding robot, which uses commercially-proven RootWave electrical weed destruction probes deployed to the plant using Igus delta robotic arms, which will be similarly boom mounted. This forthcoming version is a departure from the ‘space age’ looks of the current test rig towards a more ‘agricultural’ machine, which like Tom, will be developed to withstand the demands of on-farm operation.
A key step towards this is a partnership with motion plastics company Igus, which has supplied its delta robot arm, used commonly in industry for pick-and-place operations, to manoeuvre the probe which delivers the electrical current to the weed into place. It uses an integrated motor and encoder, linked to the Dick robot’s master controller and the three Igus delta arms fitted to each Dick can destroy weeds simultaneously.
The robot arm is a linear module in which all moving parts are plastic and self-lubricating, in order to resist dirt and dust. As there is no requirement for oil, crop contamination risks are also eliminated.
Small Robot head of prototyping Andy Hill says: “We were looking for a robot arm that was easily programmable, available at a reasonable cost and was robust enough to cope with the farming environment.
The next step is to develop its operation to work along a boom, offering back and forth and side to side movement that meets the need of the weeding pattern.
“We use the test rig in prototyping to prove the concept and check that the components are suitably robust and then move on to developing a repeatable commercial product with a partner such as Tharsus, as we have done with Tom,” he says.
Cameras mounted on the frame of Dick locate the weeds identified on the maps generated by Tom and upload their position to the Edge robot which controls the Igus arms to position the probes in the weed. Rootwave transformers convert the energy from Tesla-derived batteries to voltage delivered by the probes to destroy the weed via its roots. Workrates of 1.5 weeds/second per arm have been achieved and the process is said to work best in soils with some moisture, to provide the required conductivity.
While electrical weed destruction is the method currently being used, the robot arms could also be deployed for other types of control such as laser or microwave treatment or spot spraying.
Dick can be transported to the farm in a small van and driven into place via a remote control, before its autonomous field operation begins using GPS antennae and a base station.
Small Robot Company plans to press ahead with its ‘Farming As A Service’ concept rather than offering the robots for sale, which will include a commercial robot weeding service.
SRC founder Sam Watson Jones says: “This will be operated by SRC staff and ultimately in a contract farming service. We expect to bring in partners such as our farmer advisory group to give them the scale for commercial use of the weeding service, plus agronomy companies and agricultural contractors.
“While a 250ha block is the ideal size for the Tom monitoring robot, even on a 2,000ha farm you would not use it on the whole acreage in the first year, and we plan to rollout the service to large and small farming businesses using our partners, who themselves range from 30ha to 4,000ha.”
On-farm pilots of per plant weeding will commence in autumn 2021, with 30 farms trialling the robots including the Lockerley Estate and Waitrose Leckford Estate over the next two years, before a wider rollout.
Craig Livingstone manages the 800-hectare Lockerley Estate and is part of the Small Robot Company’s farmer advisory group. Alongside cereals, the farm also grazes 1,300 sheep in partnership with a local shepherd.
Mr Livingstone says: “We are a Leaf marque farm and are moving towards regenerative agriculture and I am hoping that robots can help us accelerate that. We have taken up Higher Tier options with grass leys and clover, extended our rotation, introduced cover crops and swapped oilseed rape for pulses.
“The obvious benefits of non-chemical weeding with Dick are an attraction, but I am also keen to use the data that Tom can provide,” he adds.
“We already carry out soil scanning using five satellite stations for GPS mapping and perform detailed analysis, use section control, etc, but where do we go next?”
Mr Livingstone says that the farm has already reduced its pesticide spend by 41% and cut fertiliser use.
“We are not organic but want to go in that direction. We would like to cut pesticides by 60% and I believe robots can help.”
He also points to the need to provide ‘public goods’ as an advantage of having more data to hand.
“We cannot put a value on not moving soil yet, but using robots for planting, for example, would contribute to this and allow us to quantify it. There is also potential to evaluate environmental gains by using sensors to record birdsong.
“Improved monitoring can certainly give us data to help to decide what to do next – or more importantly ‘not to do something’. By having precise details of soil status and green cover to combine with historical weather data we can look at the possible scenarios ahead to adjust inputs. We know it’s possible but it’s having the confidence to do it and having data to hand is the key.”