Considerations in building an spr system for rotor blade deformation measurement

Abstract

A blade deformation measurement system utilizing Stereo Pattern Recognition (SPR) technique has been designed and built. Components of the system were selected considering the size of the model rotor and target accuracy. When considering the 4 m by 3 m measurement area in order to measure the deformation of the 2.5 m diameter rotor blades, the system was designed to have a resolution of the 3D deformation data in the range of 0.1 mm. The azimuthal position of the rotor should be controlled as exactly as 0.01 degree by a time delay control of the trigger signal. The combination of Xenon stroboscope lamps with LEE 799 UV filters, cameras with Edmund 575 nm filters, and rotor blade markers painted with orange/yellow fluorescent paint provided excellent contrast. Image processing and analysis, 3D tracking and reconstruction, and measurement automation functions were validated through initial tests.