Articulated Arm Coordinate Measuring Machines (AACMMs) have gradually evolved and are increasingly used in mechanical industry. At present, measurement uncertainties relating to the use of these devices are not yet well quantified. The work carried out consists of determining the measurement uncertainties of a mechanical part by an AACMM. The studies aiming to develop a model of measurement uncertainty are based on the Monte Carlo method developed in Supplement 1 of the Guide to Expression of Uncertainty in Measurement [] but also identifying and characterizing the main sources of uncertainty. A multi-level Monte Carlo approach principle has been developed which allows for characterizing the possible evolution of the AACMM during the measurement and quantifying in a second level the uncertainty on the considered measurand. The first Monte Carlo level is the most complex and is thus divided into three sub-levels, namely characterization on the positioning error of a point, estimation of calibration errors and evaluation of fluctuations of the ‘localization point’. The global method is thus presented and results of the first sub-level are particularly developed. The main sources of uncertainty, including AACMM deformations, are exposed.

International audienceA surface morphology can be described by numerous roughness parameters. Making the most of the power of modern computers, the relative relevance of a hundred surface roughness parameters is assessed in this investigation with regard to the relationships between the morphological texture, the low wear damage and the gloss of polymer coatings. The relevance of each roughness parameter is quantitatively determined by statistical indexes of performance defined and calculated by combining the two-way ANalysis Of VAriance (ANOVA) and the Computer Based Bootstrap Method (CBBM). The fractal dimension is shown to be the most relevant parameter for characterising the different morphological textures of studied coatings and the average curvature radius of peaks for characterising the effect of wear. A linear relationship is found between the reduction of gloss and the reduction of the average curvature radius of peaks due to wear. Besides, it is also shown that angles of 85° and 20° are the most relevant for characterising, respectively, the effects of the morphological texture of polymer coatings and wear on the gloss measurements

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The influence of the morphological texture (flat and structured) of a polyester based paint coating on the low wear damage is characterised by means of roughness and gloss measurements. Using statistical methods, the aim of the investigation is to determine, among about 60 surface roughness parameters, the most relevant of them with regard to the morphological texture and the wear behaviour of polymer coatings. The level of relevance of each roughness is quantitatively assessed through the calculation of a statistical index of performance determined by combining the two-way analysis of variance (ANOVA) and the computer based Bootstrap method (CBBM).For the experimental conditions related to the present investigation, the fractal dimension and a roughness parameter directly related to the number of inflexion points of the profiles are shown to be the most relevant parameters for discriminating the different morphological textures of studied coatings and for characterising the low wear damage, respectively. Even if the gloss reduction related to the low wear damage is more visually perceptible at a macroscopic scale for the flat products than for the structured ones, the magnitude of this damage is shown to be however very similar at a microscopic scale whatever the morphological texture of the paint coatings.