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Unformatted text preview: between the mathematical model and the infinite set of points of the real surface. This repartition corresponds to the process signature. In assuming that the measured points form a representative sample of the analyzed surface, it characterizes also the distribution of the best fit residues. This condition is however not satisfied when the points are acquired with an automatic cycle using coordinates evenly distributed [Weckenmann et al., 1995]. The beta distribution was selected because it allows accounting for dissymmetrical distributions (case of turned and milled surfaces) and may also emulate a normal distribution (surfaces of high quality), depending on its parameters. A special algorithm has been developed to define the best fit of the analyzed surface, computing simultaneously the most probable parameters of the derived element and the beta distribution of the residues. Another approach can be investigated, because the signature of surface is completely defined by the machining process and the cutting parameters employed. In consequence, the probability density of the points around the surface can be predicted, prior to the calculation of th...
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- Spring '10
- The Land