Characterization of a plane on a coordinate measuring machine of large dimensions

Abstract

A technique for characterizing a horizontal plane within the measuring volume of a coordinate measuring machina (CMM) of large dimensions is described. The objective of the characterization is to obtain a correction table that allows us to minimize the mechanical errors introduced by its mechanical imperfection. The process contemplates the measurement of Y-axis yaw error and the squareness error between the X and Y axes of the machine, as well as obtaining a plane beginning with the characterization of a group of lines. This plane was then used to construct a correction table so that the uncertainty of measurement along the Z axis of the CMM could be reduced to less than 15 micrometers for any measurement carried out within an area of 4X5 m. In addition, a novel method for measuring the deviation angle of a pentaprism using the facilities of the CMM is described.