Model-based sampling plans for CMM inspection of form tolerances

BUONADONNA, PASQUALE;F. CONCAS;DIONORO, GENNARO;P. PEDONE;ROMANO, DANIELE

2007-01-01

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Abstract

We propose a method for designing CMM inspection plans of small size for use in form error evaluation of parts from batch or mass production. The method exploits a priori information coming from large sample inspection of one or a few parts of the lot. It is based on a regression model fitted to the large sample. The model is used twice. First, it provides the dominant pattern of the surface. Then, the deviations from the model that are relevant to form error are captured by weighting the points of the convex-hull of the large sample with the regression residuals. Basing on two case studies we show that the method provides enough accurate estimates of straightness and flatness and, differently from sample-based methods, is also able to make the user aware of possible outlier parts during inspection.