Research and Development in Robotic Systems

Inspection of Rotor Blade Interiors Supported by 3D Data AZuR

Visual inspection of the interiors of rotor blades is an integral part of recurrent wind turbine inspections. The limited space in a rotor blade only allows manual access in the first few meters of a rotor blade, though. Further inspection necessitates the use of remote controlled, semiautomatic inspection vehicles to examine inaccessible areas for such damage as cracks as well. In addition to purely optical inspection by means of camera systems, additional inspection tools can also be used for a more comprehensive and more user-friendly evaluation.

In the AZuR project, the Fraunhofer IFF is developing a sensor system that visualizes a rotor blade’s interior surfaces three-dimensionally based on the data from a prototype time-of-flight sensor. The compact design as well as the Fraunhofer IFF’s additional optimization of the effective range to distances of 0.05 m to 1.00 m predestines this sensor for optimal integration in the mobile inspection system. In combination with a novel recording system that scans the scene with different exposure times in a first step and computes a range image optimized for the light conditions and reflections in another step, it establishes the basis for precise evaluation of a rotor blade’s condition. Specially developed visualization software superimposes pictures from a high-resolution camera on the resulting three-dimensional image of a rotor blade’s interior surface and allows both user friendly display of the virtual 3D image of a rotor blade and easy interactive scanning and evaluation of anomalies in it.