Using drones to inspect wind turbines Monday, 05 June 2017

Researchers at the Luleå University of Technology in Sweden have successfully performed field experiments with autonomous drones, making it possible in the near future to use them for aerial inspection of wind turbines.

Wind turbines are getting bigger and bigger. The larger the wind turbines are, the more kilowatts they are capable of producing. However, wind turbines are also difficult to inspect and maintain, requiring cranes and specialised maintenance engineers to inspect both the rotor blade and the overall structure. Maintenance and inspections are costly, time-consuming and risky for the humans who carry out the inspection, and the difficulty and time required scales with the size of the turbines.

The solution is to let autonomous drones do the inspection work, says George Nikolakopoulos, Professor of Robotics and Automation at Luleå University of Technology.

With the ability of autonomous drones to perceive with great detail the surrounding environment, the process becomes faster, cheaper and safer, while yielding more reliable results from analysis and scans. The autonomous technology allows the aerial robot to work relatively independently and execute actions based on AI-driven decisions without the need for human interference.

In the team's field trials, they set up an outdoor lab in the middle of the woods in north Sweden. The lab included a wind turbine and the autonomous drones.

The drones were tasked with inspecting the wind turbine and reconstructing a 3D model of it in order to detect faults and cracks. With no reference points for the drone, the machine was challenged with building an understanding of where it is within an exterior space.

However, the drone was able to fly autonomously, and was able to precisely locate where it was in space.

The engineers credited the success in part to advances in computational power that can allow more complicated control algorithms to run on board the drones and hence perceive and process the surrounding environment much faster. Additionally, the drone benefited from the improvement of localisation accuracy based on data fusion.

The group had developed a localisation system based on the fusion of Ultra Wide Band nodes and other onboard sensors. This system is accurate to a few centimetres, even while flying. According to the engineers, the results from the experiment indicate that in two or three years, it will be possible to use drones for the aerial inspection of wind turbines.