A HYBRID APPROACH TO THE UNCERTAINTY ANALYSIS OF COORDINATE MEASUREMENTS

Abstract: In this paper, a new methodology for the uncertainty analysis of coordinate measurements is presented. The methodology can be applied on any kind of measurements performed by a CMM, and it is intended to be especially useful when performing reference measurements of geometrical and dimensional characteristics of workpieces. Master parts calibrated using this approach can be used in connection with ISO/TS 15530-3 for the uncertainty assessment of other CMMs, when measuring similar parts. Consistent measurement strategies and the real measurand definition according to the technical drawing are the foundations of this methodology, generally based in high-density measurement points. Assessment of uncertainties is performed using models in complete agreement with the measurement procedure, considering all major uncertainty contributions. Resources from artificial intelligence were applied to accelerate the development of adequate measurement procedures, simplifying the work of the CMM operator. To validate the proposed methodology, a cast iron steering case was calibrated and compared to simulation results obtained with PUNDIT/CMM, a software solution for task-specific uncertainty evaluation of coordinate measurements