The rotor and mast of a wind turbine can oscillate up to a meter in magnitude even in normal operation. This large load for the material can lead to damage and worst case to failure of an installation. So far, sensors built into the mast and rotor blades analyze these oscillations at discrete points on the equipment.
Ilja Kaufmann, Fraunhofer Institute of Optronics, System Technologies and Image Exploitation (IOSB), Ettlingen, Germany, and colleagues use laser technology to remotely measure the oscillatory pattern over the entire structure of a facility from several hundred meters away.
The centerpiece of their system is an IT-based tracking system combining a camera and a laser which are mounted on a head that can pan and tilt to follow the rotor blades. The camera records images of the installation and forwards these along to software that processes the images and builds a model of the rotary motion from the data. With this information, the pan and tilt head is positioned so that the laser automatically follows the rotor blades. The camera simultaneously collects data about the exact position of the roughly two-to-three centimeter laser spot on the rotor blade in order to stabilize it on the revolving surface.
As many points as are needed can be scanned during operation. The measurement interval is variable: the slower the oscillations, the longer the laser takes measurements. The system is compact and easily transported to the desired position using a vehicle. Due to its extended range, also offshore installations can be examined from on board a ship.
- Fraunhofer-Gesellschaft, Munich, Germany
At CeBIT the team will be displaying a prototype of the diagnostics system: Fraunhofer booth, hall 9, booth E40
