Rotating machinery parts, e. g. roller bearings or turbine engines, are present in many industrial applications.
Within this paper, a metrology system for determining the out-of-plane and in-plane deformation and vibration of
rotating objects is presented. The system consists of an optomechanical image derotator, which is combined with a
high speed camera and a scanning Laser-Doppler-Vibrometer (LDV). The image derotator is used to measure
deflection and vibration in a coordinate system fixed to the rotating object. To demonstrate the capability of this
measurement system, examples of high relevance in industrial applications are considered.
A self-developed optical image derotator is applied for the analysis of the dynamic behaviour of rotating objects under
operational conditions. This makes it possible to get a stationary image of the rotating object. Using the combination of
image derotator and a high speed camera or a laser Doppler Vibrometer in-plane and out-of-plane vibration of rotating
components with a rotational speed of up to <i>n</i> = 10.000 min<sup>-1</sup> can be measured. The main component of this derotator is a rotating Dove prism. The prism causes aberration and polarisation effects that affect the measurement quality. To
improve the optical and mechanical characteristics of the derotator and to expand its application potential, IMR develops
a new derotator generation which uses an arrangement of mirrors instead of the Dove prism. Thereby it is additionally
possible to do thermo-graphical measurements of the rotating machinery components. It is also possible to examine the
objects with rotational speeds up to n = 20.000 min<sup>-1</sup>. In this paper the design and simulation of the optical module of the
new derotator are introduced. Furthermore, the mechanical construction of the derotator will be explained.