Researchers at the National Renewable Energy Laboratory (NREL) of the US Department of Energy have effectively used robotic assistance in the production of wind turbine blades to reduce labor-intensive conditions for humans and possibly increase product consistency. The study was published in the journal Wind Energy.
NREL researcher Hunter Huth stands beneath a robotic arm designed to automate a portion of the blade manufacturing process. Image Credit: Werner Slocum, NREL
While robots have been employed in the wind energy sector for tasks such as painting and polishing turbine blades, widespread adoption of automation has been limited.
However, research conducted in the laboratory showcases a robot's capability to perform intricate tasks like trimming, grinding, and sanding blades. These crucial steps come after the creation of the blade's two sides using a mold, which are then bonded together.
I would consider it a success. Not everything operated as well as we wanted it to, but we learned all the lessons we think we need to make it meet or exceed our expectations.
Hunter Huth, Robotics Engineer and Study Lead Author, National Renewable Energy Laboratory
The co-authors of the research, all from NREL, include Casey Nichols, Scott Lambert, Petr Sindler, Derek Berry, David Barnes, Ryan Beach, and David Snowberg.
The manufacturing of wind turbine blades involves post-molding operations that typically require workers to operate on scaffolding while wearing protective suits, including respiratory gear. The researchers highlighted that automation in these processes will not only enhance employee safety and well-being but also assist manufacturers in retaining skilled labor.
This work is critical to enable significant US-based blade manufacturing for the domestic wind turbine market. Though it may not be obvious, automating some of the labor in blade manufacture can lead to more US jobs because it improves the economics of domestic blades versus imported blades.
Daniel Laird, Director, National Wind Technology Center, National Renewable Energy Laboratory
Huth said, “The motive of this research was to develop automation methods that could be used to make domestically manufactured blades cost competitive globally. Currently offshore blades are not produced in the U.S. due to high labor rates. The finishing process is very labor intensive and has a high job turnover rate due to the harsh nature of the work. By automating the finishing process, domestic offshore blade manufacturing can become more economically viable.”
The study was conducted at NREL's Flatirons Campus, specifically at the Composites Manufacturing Education and Technology (CoMET) facility. The robot operated within a 5-meter-long section of a blade, despite wind turbine blades being significantly longer. To address this challenge, a robot would need to be programmed to work on each section of the larger blades individually, as they tend to bend and deflect under their own weight.
Using a sequence of scans, the researchers were able to precisely identify the front and rear sections of the airfoil - a unique blade shape that facilitates smooth airflow over the blade - and create a three-dimensional representation of the blade’s position.
Subsequently, the group coded the robot to execute an array of tasks, following which its precision and velocity were assessed. The researchers concluded that there was potential for improvement, particularly in the area of grinding. The robot ground down the blade too much in certain places and not enough in others.
“As we've gone through this research, we've been moving the goal posts for what this system needs to do to be effective,” said Huth.
The performance of the robot was not directly compared to that of a human undertaking the same tasks.
Huth said, “An automated system would provide consistency in blade manufacturing that is not possible when humans are doing all the work. He also said a robot would be able to use ‘tougher, more aggressive abrasives’ than a human could tolerate.”
The research was funded by the Advanced Materials and Manufacturing Technologies Office of the US Department of Energy.
Journal Reference:
Huth, H., et al. (2024) Toolpath generation for automated wind turbine blade finishing operations. Wind Energy. doi.org/10.1002/we.2913.