Strawberry-picking robot uses ultra violet light to control funguses

BSC Electronics is a world leader in fibre measurement instruments. “There is a lot of expertise in image processing and robotics in this company”, says engineer Robert Walker of BSC Electronics. “So, we are always looking out to see how we can use our expertise for other products.”

COVID stimulated development of strawberry-picking robot

The developments of the strawberry-picking robot started in 2020, Mr Walker explains. “Our borders were closed because of COVID. We saw that some growers here lost money, because they couldn’t get overseas labour to come in. One grower in particular, we spoke to, lost 200,000 dollars.”

There is a demand for something simple

The engineers of the company decided to build a small robot, and came up with the name Outbackrobotics. “There are some strawberry-picking and apple-picking robots, that are the size of a room”, Mr Walker says. “And they are very expensive. That’s not what is needed. Growers need something the size of a human being, that can do the work that is currently being done by humans. We have been talking about this to berry-growers and government departments. There is a demand for something simple.”

In the past two years, the company has designed and built a prototype that works best with hydroponic strawberries, which are grown around waist height. “In Australia, probably a quarter of the farmers grow hydroponic strawberries, usually under cover but in open outdoor fields. I think there is a move towards growing strawberries this way. But we could modify our robot, to pick strawberries on the ground.”

Also read: Australian harvesting robot picks apples in seven seconds

Lease strawberry-picking robot instead of buying

Mr Walker says that berry-growers in Australia have a problem with getting enough human pickers, but still get nervous about investing in robots. “So, we do not want them to buy the robots. We would like to lease them, for around the same rate as a human would cost. The robot picks slower at the moment, about half the speed of a human picker, but you can run it 24/7.”

And the strawberry-picking robot has another capability. It uses ultra violet light (UVC-light) to control funguses. “This method has been well proven overseas. In the US, they have discovered that, if you radiate the funguses at night-time – when they shut down and are dormant – they have no mechanism for repairing themselves. It is very effective. If humans do this, they will have to work at night. That’s where the robot comes in, moving autonomously down the aisles. And you only have to do it once a week to stay on top of the fungi.”

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No fungicides needed

The biggest advantage of using the UVC-light, is that growers don’t need fungicide to treat the plants, Mr Walker points out. “That means that they can certify themselves as organic and get more for their strawberries. And fungi are the most important threat for the strawberry-plants, with powdery mildew being the most dominant fungus.”

The strawberry-picking robot gets its power from a battery. It can run for 10 to 12 hours before the battery needs to be swapped. “But we can put a bigger battery in there, if we pass the prototype stage. So, it could work for 24 hours a day, if you’d want to. We would also put lights on it.”

Most parts are 3D-printed

BSC Electronics has 3D-printed most of the parts of the strawberry-picking robot. It is 1.56m high, 1m long, 0.6m wide and has a turning radius of zero-turn. The robot uses one picking-arm, a cutter and two Intel RealSense LiDAR colour (3D) cameras to pick the ripe strawberries. It uses machine-learning and has a GPS based system on-board for navigation.

One person can easily work with a group of five of these robots

“There are two GPS-sensors and a base station”, Mr Walker says. “That allows you to become much more accurate. The robot knows where it is in the world within a few centimetres. Once the tray is full of strawberries, it autonomously moves to the shed, where a person can take the tray off. One person can easily work with a group of five of these robots.”

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Farmers in the Perth area have given BSC Electronics the opportunity to prove the technology. “It is working well. But farm-workers have come into the country again to pick strawberries, so we put the project on hold for a while. Strawberry growers in Australia are now hesitant to try it. They are certainly interested but I think no-one wants to be the first person on the block to try it out.”

Curious what (harvesting) robots are curently commercially available? Then check out our Field Robot Buyers Guide!