A priori estimation of measurement uncertainty as a tool to improve verification of geometric product specifications with coordinate measuring machines

Abstract

Geometric product specifications (GPS) are critical for ensuring the functionality and interchangeability of mechanical components. Coordinate measuring machines (CMMs) are commonly used to verify these specifications, but choosing an appropriate measurement strategy and evaluating of the metrological capability of CMM-based measurement processes remains challenging. This work evaluates the applicability of a simulation-based a priori method − the VCMM-User method − for estimating the measurement uncertainty of CMM measurements, with the aim of optimizing the measurement strategy and evaluating the capability of the measurement process. It presents a description of the VCMM-User method and the results of a set of validation simulations. Further simulations demonstrated the effect of scanning speed, probing mode, and point density on measurement uncertainty, highlighting the method’s usefulness in optimizing measurement strategies. A procedure for evaluating measurement process capability is proposed, combining simulated uncertainty with experimental reproducibility analysis. A case study using a gap gauge illustrates the method’s practical application and limitations, particularly in tight-tolerance scenarios. The VCMM-User method thus offers a practical and efficient tool for improving measurement planning and assessing process capability in industrial metrology.