Uncertainty determination for CMMs by Monte Carlo simulation integrating feature form deviations

Reliable quality control is impossible without specification of the measurement uncertainty. For coordinate measuring machines (CMMs), Monte Carlo uncertainty evaluation allows to integrate the many task specific uncertainty influences. Incorporating the influence of feature form deviations in such simulations is difficult. This paper shows that limited sampling in combination with feature form deviations is often the most important uncertainty contributor for CMM measurements. A method that determines uncertainties for feature measurements on CMMs is proposed. The influence of feature form deviations is taken into account. The method is integrated in CMM software. The results are validated on actual workpieces.