Igus delta robot provides chemical-free weed killing
With herbicide-based blanket weed-killing regimes becoming increasingly expensive and increasingly ineffective, Farming-as-a-Service start-up the Small Robot Company is offering a robotic alternative that uses artificial intelligence to identify and kill weeds on an individual plant basis. Central to the operation of the system in these most challenging of outdoor conditions are delta robots from Igus.
Use of herbicides in farming has come under close scrutiny in recent years, with questions being asked about the environmental consequences of indiscriminate weed killing regimes. Further, at a time when the cost of herbicides has increased by around 50%, it is estimated that a blanket approach results in the wastage of about 95% of the chemicals.
A solution to the problem comes from the Small Robot Company (SRC). Andy Hall, head of prototyping at SRC, said: “The opportunity here is for selective weeding rather than blanket weeding, delivering a per-plant farming approach.”
For example, there is a benefit in keeping weeds such as clover, which converts atmospheric nitrogen into a plant-usable form. But farmers want to eliminate harmful weeds such as black grass, which it is estimated costs the farming industry in the UK some £400m per year, and rising.
The solution from SRC is built around two autonomous robots. The first, named Tom, is equipped with cameras and a GPS system to photograph and tag the location of every plant in a field. A cloud-based AI system, named Wilma, then processes the data to differentiate between crop plants, ecologically useful weeds and harmful weeds.
Using this data, the farmer can make informed decisions about which weeds need to be killed. And this is where the second robot, Dick, comes into play, with on-board technology to enable weed killing on an individual plant basis.
Currently at working prototype stage, Dick is a lightweight robot that runs on four wheels, minimising ground compaction. Suspended beneath it are four Igus delta robots, each equipped with a voltage carrying tip. At each weed killing site, the delta robot touches the weed with the tip and a high voltage is transmitted into it to kill it.
Delta robot arms from Igus were selected for their precision, low-cost and lubrication-free engineering. The delta robot is built around standard Igus drylin self-lubricating plastic parts in an aluminium linear system. Lightweight and inherently resistant to dust and dirt, it has proved ideal for use in the challenging farm environment, as well as being ecologically friendly since no lubricants are required.
An essential feature of the delta and Igus components is they are lubrication-free. Lubricated moving parts like the belt drive and bearings would potentially clog up with soil and water in a muddy field, but Igus polymers and parts are designed to be dry running.
Hall added: “With the plastic parts being lubrication-free, it’s also an environmentally friendly solution. The delta robot is also very robust, and it’s very strong – in fact it’s surprised us just how strong it is. Further, the controller is not affected by the high voltages being transmitted through the tip, and programming is easy – we found it very easy to code it ourselves.”
With this robotic approach, SRC is looking to offer a ‘Farming-as-a-Service’ model to tackling the problem of weed control. SRC and Igus are looking to work on different actions, where Tom and Dick could combine again for spot spraying, spot fertilizing or slug killing, for example.
“The milestone we’ve hit is that we can now take action at the plant level,” said Hall. “Using artificial intelligence, the robots can recognise the weeds and target the robotic arm onto those weeds. At that point we can do anything we want. Our robotic platform incorporating the Igus arm could have many different technologies bolted on – and the world’s our oyster on that.”
Igus UK managing director Matthew Aldridge commented: “Because the delta is lightweight and low-cost it has opened up new opportunities for these robots to be used in mobile applications, proving a new technology in a harsh outdoor environment. Igus is planning to work with SRC on new industrial applications where precise and low impact actions are needed on farms and potentially other scenarios.”
Ben Scott-Robinson, CEO and co-founder, Small Robot Company, said: “To prove the power of per plant farming, we are focused on answering the biggest problem that farmers face at the moment, which is weeding. We’ve proved we can deliver per plant weeding: a world first. The focus for us now is being able to move forward to deliver this repeatedly, and at scale. This will be game-changing.”
Following successful field trials, the next stage for Tom and Dick are efficacy trials, measuring the force required to destroy the weeds, including the comparison of different varieties, to ensure that they are destroyed rather than partially killed.
Visit the Igus website for more information
