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The robots that can pick kiwi-fruit


Unable to find the seasonal labour they rely upon to harvest fruit and vegetables, many farmers have been faced with leaving their crops to rot in the fields during lockdown. But one New Zealand company is working on a solution.

We started getting calls shortly after the coronavirus lockdowns began. Hidden behind the human health risk posed by the pandemic, another crisis has been unfolding.

In fields around the world, ripening fruit and vegetables that should be getting picked, packaged and shipped to supermarkets were instead at risk of being left to rot in their fields. Farmers have been struggling to find the people they needed to harvest them.

Labour shortages are a problem that has been on the horizon for some time. There are few permanent farm workers anymore. Millions of migrant workers, students, gap-year travellers and retired folk looking for some extra cash make up the majority of the seasonal workforce. But with more and more people moving out of rural areas and into cities, it has left farms in many parts of the world with a growing challenge – they increasingly struggle to find enough people to do this hard, dirty work.

So, larger growers in many areas have resorted to flying in specially recruited workers from abroad to help. Here in New Zealand many growers rely upon labour from the Pacific Islands, but as borders closed and flights stopped, suddenly the industry has been left scrabbling around.

Governments across Europe have asked staff from other industries – currently out of work due to the lockdowns – to help out with the harvests. In the UK, for example, the Prince of Wales recently appealed for “an army” of people to help harvest fruit and vegetables in the country’s fields while its government launched a “Pick for Britain” campaign.

The coronavirus has now shone a light on just how precarious this situation is. It’s led a few farmers – who we have met, talked to and worked with in the past – to reach out and ask for our help.

A UGV robot monitoring underneath the crops

Autonomous vehicles that can navigate in orchards can monitor and harvest crops around the clock (Credit: Robotics Plus)

Over the past decade, we have been developing smart robots capable of navigating orchards, recognising fruits and harvesting them. It is exactly the kind of automation that could have eased the labour shortages and allowed production to continue. We now want to make sure that farmers don’t have to find themselves in this situation again.

We have one robot that is already being used in the US, New Zealand and Europe that may have been helpful for growers at a time when labour is short. Our automated apple-packer uses suction to delicately pick up apples from a conveyor, place them in display trays and orientate them so the side with the best colour is facing upwards. It uses a lot of smart vision to do this, recognising the fruit, the style of the trays being used and the colour of the apples.

It can pack about 120 apples a minute, so it is much faster than a human, and much more consistent – it doesn’t get tired and the fruit gets fewer bruises, even at top speed.

While robotics is not likely to help much in the immediate crisis, it is focusing people’s minds in a way that is likely to accelerate the move to automation in farming

But to have a real impact there needs to be automation throughout the process. This is why we have been developing unmanned ground vehicles that can navigate their way through orchards and fields. They use sensors to map the environment so they can get close to plants without damaging them.

On top of this platform we are working on a number of solutions that can be clipped on top, much like a farmer’s tractor. One of these is our kiwi-fruit harvester, which was initially developed by my co-founder Alistair Scarfe during his PhD at Massey University, in Palmerston North, New Zealand. He has proven that it is possible to use a robot to identify fruit, reach up, pull it off the plant and collect it on a hopper. Mounting this on a mobile platform means it can harvest fruit, sort them into bins by size and deliver them to the pack house before driving back out to carry on picking.

Kiwi-fruit are relatively easy as they hang down from an overhead canopy, but we hope to use this proof of concept to transition to other fruits.

Alistair Scarfe and Steve Saunders want to automate the dirty, dangerous and dull jobs in farming (Image Credit: Robotics Plus)

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Some crops, such as asparagus, still require a certain degree of skill to harvest, so recruiting inexperienced people to help out in a time of crisis has also proven extremely difficult. But we have also been developing an automated asparagus-picker that moves along the rows, using machine vision and artificial intelligence to detect the spears before grasping and cutting them.

We have already tested a prototype on farms in New Zealand and in California, using what we have learned to improve the technology. But it is not quite as simple as turning these machines out on a production line to send out to farmers around the world. It is going to take some serious investment to produce a commercial product that farmers can use.

Few growers or horticultural industry bodies have the kind of money they can invest up front to bring technology like this forward. But it is also more than just finding the financing – we also need to collaborate to ensure the technology can work for everybody.

At the moment, asparagus farmers in different parts of the world grow their crops in different ways. Some use raised beds, others mounds of soil, while there are some, like in New Zealand, where it is grown on flat ground. In some places they harvest by cutting the asparagus spears above the soil bed, others cut just beneath the soil.

When you have this amount of variation in how a crop is grown and harvested, it makes building a robotic solution that works for all of them very challenging. If the industry wants to move towards automation, there is going to need to be some degree of standardisation.

A robot paking apples into a carton

Suction cups allow the apple packing robot to orientate fruit without damaging them (Credit: Robotics Plus)

And this is what we are now working on. We are trying to put together a global consortium of farmers, producers and industry bodies who we can collaborate with. So, while robotics is not likely to help much in the immediate crisis, it is focusing people’s minds in a way that is likely to accelerate the move to automation in farming.

There are some jobs robots simply cannot do though. Robotic arms and vision systems are not very good at getting clusters of fruit that are hidden behind branches or leaves for example. Nor will it replace the farmer’s expertise. I own an orchard myself, and still love getting my fingers on the plants. It is hard to replace that experience. But robots can free up people to do other jobs that cannot be automated. They can help farmers get more from their land.

Automation will not just help to ease labour shortages in farming but can keep workforces safe by allowing them to social distance more effectively. With fewer people touching the produce, it should be more hygienic too. In three to four years from now, we can expect to see more of this technology in the fields than we otherwise would.

What has become clear in recent months is that farming has to change if we still want to put food on people’s tables. If it is done correctly, the next few years could be very exciting.

This interview with Steve Saunders, co-founder of Robotics Plus in Tauranga, New Zealand, was adapted by Richard Gray.

This article is part of Follow the Food , a series investigating how agriculture is responding to environmental challenges. Follow the Food traces emerging answers to these problems – both high-tech and low-tech, local and global – from farmers, growers and researchers across six continents.