Wind turbines are not as simple as we see them. They apparently looks like a big tower that just spins and are a great source of clean power. But originally, they are as complex as other systems of energy are and they also need care, otherwise they can fail with disastrous consequences. Thankfully, the enormous blades of turbine can now be inspected autonomously with the help of a robot created by Sandia National Labs researchers.
As we drive, we see these enormous towers that collect energy from wind currents just for some minutes or even seconds. But, the wind turbine suffer from inclement weather, temperature extremes, and also from lightning strikes, as naturally they are the tallest things around. Despite of these changes, they must stand for years, and for this these things need to be inspected regularly.
Because of their enormous design, the inspection of these turbines is very difficult and superficial also. As these blades are often installed in distant or inaccessible areas, you can see them offshore. Also these blades are among the largest single objects manufactured on the planet. In a news release, Sandia’s Joshua Paquette explained:
“A blade is subject to lightning, hail, rain, humidity and other forces while running through a billion load cycles during its lifetime, but you can’t just land it in a hanger for maintenance,”
You can say that crew has to go to the dangerous locations for inspecting the turbine. They often have to do those inspections on structures hundreds of feet tall. Using a crane is another option we can think but, using it the inspection will not be easy as well. Inspection may be no more than eyeballing the surface. According to the Paquette:
In these visual inspections, you only see surface damage. Often though, by the time you can see a crack on the outside of a blade, the damage is already quite severe,
As better and deeper inspections are needed, so the team partnered with International Climbing Machines and Dophitech, and decided to work on this. The crawling robot is the result of their research. This robot move along a blade slowly but surely, documenting it both visually and using ultrasonic imaging. Cracks or scuffs on the surface will be seen by the visual inspection and ultrasonics penetrate deep into the blades, making them capable of detecting damage to interior layers well before it’s visible outside. It can easily do it on large surface by moving side to side, bottom to top.
It is quite slowly and requires human oversight right now because it just comes straight from the lab. But, in future for closer inspection or scanning team may attach one to each blade, and come back a few hours or days later to find problem on the areas marked.
Researchers also worked on another approach that is drones. High-resolution cameras are equipped in these drones and infrared sensors that detect the heat signatures in the blade. The damage in the blades can be detected by them as the thermal properties changes on the damaged spots.
These automated systems can be used together in future. A drone could let crews know whether any particular tower needs closer inspection or not only by passing by, and then for a closer look it can trigger the live-aboard crawler.