A new AutoFill docking system for SwarmFarm Robotics’ autonomous pivot-steer tractor units means they can top up their spray tanks without human intervention.

Once the liquid level falls below a defined threshold, the SwarmBot will trundle back to its loading station to fill either a prepared spray mix or water and chemical separately – the latter through a direct injection setup that sucks the liquor straight from a container.

Accurate flow meters ensure the mix is on point.

See also: £50k Sabanto Steward kit gets Fendt 700s working autonomously

This will be particularly handy for biologicals and other high-rate products that require regular fill-ups, drastically reducing the manpower involved in what was already a labour-light system.

© MAG/Oliver Mark

Buyers can also spec an on-board weather station to ensure the machine is working in suitable spraying conditions.

The same auto-fill system isn’t yet available for diesel but, says the company, it’s a less pressing issue, as the Bots can manage up to 26 hours of work from their 210-litre tanks.

Apparently, these efficiency gains mean one 27m/3,000-litre SwarmFarm machine can match the output of a self-propelled sprayer weighing four times more and with twice the boom width.

Another relatively new option is green-on-green spraying, courtesy of French firm Bilberry.

The technology is fitted on Goldacre booms, offering the ability to target specific weeds with more expensive crop protection products to beat resistance build-up.

Alternatively, growers looking to improve precision can spec a green-on-brown system for stubble spraying, using kit from either Weed It or Weedseeker.

Such has been the success of the SwarmFarm platform in its home market that, last year, it sold more Weed It-equipped sprayers than any other manufacturer.

As for the spray pack itself, buyers can pick from a range of setups provided by third-party suppliers.

Rather than building its own attachments, it has 18 manufacturers signed up to its SwarmConnect platform, allowing their implements to be integrated into the control system.

© MAG/Oliver Mark

Pivot-steer tractor

The latest iteration of the 2.5t tractor unit, dubbed SwarmBot 5, has remained largely unchanged since its commercial launch in 2018.

“The concept of an autonomous tractor might seem complicated, but the actual machine is incredibly simple,” says SwarmFarm founder Andrew Bate.

“It’s easier to repair and maintain than anything on the market – basically supersized Lego.

“You could swap an engine in little more than an hour and a hydraulic pump in 45 minutes, unbolt the axles, add or alter components, and generally configure it however you want.”

Propulsion comes from an 86hp Hatz four-cylinder diesel mounted at the front of the articulated chassis.

This powers a hydraulic pump that drives individual motors for the four equal-sized wheels, available in various diameters up to a maximum of 1.1m.

Most of the post-launch tweaks have centred on the drivetrain, ostensibly to produce more torque at a reduced top speed of 10kph. As a result, it can now handle gradients of up to 15%.

Implements are either towed via a drawbar, or mounted on a three-point linkage.

© MAG/Oliver Mark

Setting it up

To get started, owners must first map field boundaries or import RTK-grade maps. SwarmFarm’s software then joins all the information together.

It’s also possible to include a farm track network, allowing the Bot to move between fields autonomously rather than being towed.

Routes can then be planned, verified and uploaded to the tractor unit ready for work.

A GPS system provides guidance, with Lidar sensors detecting obstacles such as trees and fences – but not yet watercourses – and a combination of 4G and wi-fi (or Starlink for regions with poor cellular coverage) allowing it to communicate with the firm’s smartphone app.

At present, there is only one front-facing on-board camera but, with the cost of this hardware falling, more may be added in the future to provide a full 360deg view.

Other safety features include an emergency stop, a crash-sensing front bumper, and a geofence – beyond which it cannot travel.

© MAG/Oliver Mark

How much?

List price of the tractor unit is A$304,750 (£152,000), with the buyer then free to purchase implements direct from partner manufacturers.

A 24m boom with Weed It spot-spraying technology is likely to add another A$300k (£150,000).

Having sold its first machine in 2018, the company now has over 120 commercial units in operation in Australia.

Between them, they have completed more than 2.1m ha of spraying and mowing, clocked some 220,000 autonomous hours, and are said to have saved 1m litres of chemical.

And with production capacity ramped up with a new manufacturing and assembly hub, plans are afoot to branch into new markets such as horticulture and cotton seeding.

However, broadacre drilling is likely to remain the business of a manned tractor in the medium term, with the company instead focused on monotonous, repetitive tasks that offer the biggest return on investment.

“Labour savings are the obvious advantage when it comes to mowing and spraying, freeing up staff to focus on higher value work rather than repetitive field passes,” says the firm’s software engineer, Angus Ross.

“But this technology is also helping to bring more young people into the industry. It’s like a new sector of agriculture.”