Geometrical checking by virtual gauge, including measurement uncertainties

  • Mailhe J.
  • Linares Jean-Marc
  • Sprauel J.M.
  • Bourdet P.

  • Coordinate Measuring Machine CMM
  • Uncertainty
  • Geometric Modeling


For the most part, metrology software is currently based on the calculation of distances or angles between geometrical elements. This kind of method implies series of geometrical constructions which are amplifying measurement uncertainties. Usually, the estimation of error bars is then done after the geometrical verification. Hence, uncertainties are not directly taken into account during the checking process. To avoid these impediments, a new checking method, based on virtual gauges, is proposed in this paper. Based on Gram matrix, virtual gauges permit to perform checking without any intermediate geometrical construction. Moreover, thanks to a statistical description of the specified surface, the measurement uncertainties are thus directly taken into account during the conformance test process. An example of application is presented to demonstrate the relevance of this approach.