Non-intrusive in-flight Propeller Blade Deformation Measurements by Means of a Rotating Camera

Abstract

The Image Pattern Correlation Technique (IPCT) is a powerful optical tool to measure the surface shape and deformation of aircraft structures, e.g. wings, propeller or rotor blades, non-intrusively in flight. The latest development of this technique is its application to 360° propeller deformation measurements. Therefore a special stereo camera system rotating with the propeller at its full rotational speed was designed, whereby the system was exposed to extreme vibration and centrifugal forces. By beginning of 2014 the whole system had been successfully tested on an Evektor VUT 100 COBRA airplane. In the paper, this highly sophisticated rotary camera system and the measurement technique IPCT is described. Furthermore some results of the first flight tests are presented.