Wind Workers
February 21, 2009
Wind turbine generators already dot the horizon for miles in every direction in many parts of the world. Tending the windmills has been an arduous task for human technicians. Rotor blade damage is a routine but annoying problem that entails many hours of maintenance.
But now, scientists at the Fraunhofer Institute for Factory Operation and Automation (IFF) in Germany have said they are perfecting a generation of robots which will be able to monitor and maintain wind turbine generators on a round-the-clock basis.
Their latest development is RIWEA, a robot that inspects the rotor blades of wind energy converters.
Primarily made of glass-fiber reinforced plastics, rotor blades have to withstand wind, inertial forces, erosion, and other forces. Until now, humans have inspected wind energy converters at regular intervals in a time-consuming process that involves the technicians closely examining large surfaces -- a rotor blade can be up to 60 meters in length -- at airy heights.
Better than humans
The researchers say they hope to make some of those inspections a thing of the past.
"Our robot is not just a good climber," said Dr. Norbert Elkmann, a project manager at the Fraunhofer IFF. "It is equipped with a number of advanced sensor systems. This enables it to inspect rotor blades closely."
The inspection system consists of three elements: an infrared radiator conducts heat to the surface of the rotor blades, a high-resolution thermal camera records the temperature pattern and thus registers flaws in the material, and an ultrasonic system and a high resolution camera are also on board, thus enabling the robot to detect damage that would remain hidden to the human eye.
A specially developed carrier system ensures that the inspection robot is guided securely and precisely along the surface of a rotor blade.
The advantage of this system is that it can do its job on any wind energy converter -- regardless of whether it is large or small, on land or offshore, where wind farms are increasingly being built.
The robot delivers an exact log of the rotor blade condition, and reportedly never fails to spot hairline cracks or other potential problems.