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Drones for energy

5,000 km of high-tension grid

to be disrupted

A new Danish research project will save millions on inspecting high-tension cables. The goal is for autonomous swarms of drones to cut costs by 95 per cent.

It sounds like science fiction. A swarm of drones fly like birds from pylon to pylon, settle on the cable to charge up, and then fly on, while watchful lenses capture and report irregularities. With no human involvement whatsoever.

This is what a new Danish research project is aiming at, with DKK 19 million (EUR 2.5 million) in funding. Inspection of the high-voltage grid is a costly undertaking today, and drones have long since shown their value as inspectors in the construction industry.

“Cables need to be inspected for corrosion and the like. It’s an important job, and a cable break is a high-risk affair. We do the job today with a camera operator in a helicopter. And that’s hugely expensive. Afterwards, inspectors sift through thousands of images, making the process even more costly. So we propose using drones. Drone inspection already exists, but here we’re taking it a giant leap forward,” says Associate Professor Rune Hylsberg Jacobsen.

Much better and far cheaper

The Danish transmission grid consists of about 5,000 km of cables. Inspection by helicopter costs DKK 1 million (EUR 132,000) per week, so there’s money to save if the project is successful. A lot of money.

The drones will be able to control themselves without human interaction. They will be able to recharge themselves by latching onto the high voltage cables, and they will autonomously be able to avoid collisions with everything from pylons and cables to other drones and birds. By cutting out the helicopter, the pilot and the photographer, drones can save 95 per cent of inspection costs and provide much better quality images.

By means of artificial intelligence, a computer can automatically filter the images, so that the human inspectors can concentrate on looking at the images that actually show irregularities.

Robust technology

Rune Hylsberg Jacobsen is heading the communication part of the project. This is the part dealing with how the drones contact each other: and there’s a lot to do:

“Our task is to look at communication between the drones, so that we can make an autonomous swarm of drones that can work together. You let them loose, and then they have to be able to work together on their task without human intervention. This entails a lot of communication challenges. The drones have to know where they are in relation to each other, they mustn’t fly into each other, and they need to know which part of the work has already been done, etc. So the communication must be robust. Therefore, we’re looking at what wireless technologies we can use for the project,” he says, and then gives an example:

“We’re looking at different sensors we can fit on the drones so that they can “see” like bats. We can also use different types of navigation technology such as GPS, and to avoid collisions with cables, we can use other sensors that tell the drone when it’s getting too close to the magnetic field formed by the high voltage.”

Can be used in many other places

So far, the project will run over three years, and the plan is for the drones to be able to fly their missions independently and completely automatically. They’ll get a start signal and then fly off from their base, find the cables, follow and inspect them, take pictures, recharge, and then fly home when they’ve finished their day’s work.

Even though such a swarm of drones can save enormous sums on cable inspection, this is far from the only use for the technology. Inspections of other installations constitute a huge area, where this type of autonomous drone technology could have far-reaching consequences.

And parts of the technology can be used elsewhere. For example, as Rune Hylsberg Jacobsen explains, the communication system between the drones is similar to what is being developed for autonomous agricultural machinery.