Robots roaming pastures soon a reality

“We’re aiming to launch at Mystery Creek 2014,” says Geoff Bates of Callaghan Innovation and Pastoral Robotics. “The plan is to have a limited release on up to 10 farms we can monitor closely.”

If that goes well, the first truly commercial models of the robotic urine-patch treatment machine, dubbed the Mini-ME, will be available for the 2015-16 season.

The detail of how the Mini-ME will operate is spelt out in a paper Bates and fellow developer Bert Quin, of Pastoral Robotics, will present at next month’s New Zealand Grassland Association conference.

At the heart of the machine is patented new technology which identifies urine patches. Crucially, it can do that immediately after cows leave a paddock, without waiting for grass to change colour. “By the time you’ve got vibrant growth it’s too late: you should have been treating the urine patch five or six days earlier,” notes Bates.

Such treatment also negates the risk of DCD contamination of milk as it will typically be at least 28 days before pasture is grazed.

Not that the development is dependent on the moratorium on DCD use being lifted, as there are alternatives such as urease inhibitors which, given the timeliness of the intervention, would be effective at slowing the nitrate release.

“It would great if they can get the [DCD] issue sorted and they say we can use it but this product is still relevant either way,” says Bates.

To find urine patches the Mini-ME traverses the paddock in a pre-programmed route, scanning as it goes, and making applications where necessary. At under 50kg fully laden and travelling at 5km/h or less, the machine poses little risk to humans, animals or fixed assets. Should a collision occur it will simply stop and alert its operator.

The machine’s not just for dealing with urine patches. It’s envisaged that as it passes over dung pats a drag chain or small plough will spread the manure over twice or three times the normal area.

Covering 3m per pass at 5km/h the machine would cover 1.5ha/hour. Given that a herd of 600-800 cows would normally graze 4-8ha/day, that means it will easily be able to treat the pasture grazed by the herd each day.

Users will need to move the robot to each new paddock, starting it at a designated point in each paddock for it to follow the preloaded route; obstacles such as troughs or trees need to be mapped in the programming process, but that’s a job that only needs doing once for a farm.

Rechargeable batteries will need changing, and the 20L spray tank topping up, then it’s just a case of pushing the button and off it goes to work. When it’s finished the paddock it will stop at the programmed stop point ready for moving to the next paddock.

Bates says the design means it can cover any country a cow is comfortable on and it won’t tip over. “It’s much more stable than a quad bike.”

Ultimately, he envisages every farm will have such a machine, but initially it will be the larger, most likely South Island farms, that it will suit. “Where they were spending $10,000/year applying DCD all over the property, that’s where it becomes economic.” Environmental regulations may also prove a driver for use in certain regions, he notes.

While the Mini-ME is likely to be the first product off the shelf – or rather robot on the paddock – a larger ‘XT’ version with an extra spray tank is envisaged that will apply liquid urea, trace elements and other pasture additives as required. “Application of urea will be linked to urine detection so the urea delivery cuts out over urine patches.”

Applying 50kg/ha of fluidised urea (23kgN/ha) using a 25L tank will require 16 refills to cover 8ha, so Bates and colleagues are working on automated docking with a tanker positioned at the start-stop point in the paddock. “The robot will use differential GPS (DGPS) for general location, and onboard sensors to locate the coupling point and guide Mini-ME XT into the refilling position.”

Eventually, a considerably larger robot, dubbed Maxi-ME, is envisaged, which would perform all the functions of the Mini-ME models but also be able to spread effluent and other bulk fluidised fertilisers such as phosphate and potash. It would be designed to operate 24 hours/day, with a 3000-5000L product tank. As such, the electric-powered robot’s likely to be 3m long, 2m wide, and 2m high, and weigh up to 7t fully loaded.

Bates and Quin predict it will use only a quarter of the power of a comparable tractor and effluent wagon, and of course, there’s no driver required. However, no driver means many more safety features must be built in so it stops before hitting anything – animate or inanimate.

The benefit of such a large-scale robot is it will track back to a central point on the farm to refill with effluent, fertiliser, or other product for application, not to mention the precision application and management of the whole farm without having to leave the farm office.

Bates says the application of the GPS, robotic and sensing technologies to manage nutrient applications and losses in a pastoral setting is, as far as he’s aware, unprecedented globally.

“There’s a lot of potential. Australia’s dairy industry has some similar environmental problems to us and in Europe there’s a demand for this type of technology as a labour replacement, as well as the environmental aspect.”