UNCERTAINTY ANALYSIS OF A LASER CALIBRATION SYSTEM FOR KINEMATIC ACCURACY ASSESSMENT OF MACHINE TOOLS

摘要

1) A study of the uncertainty components that make up the uncertainty budget of the kinematic error calibrator has been carried out. The sources of uncertainty that have been considered are the following: trigger device repeatability, laser wavelength uncertainty, electronics error, optics non-linearity, wavelength compensation, material thermal compensation, optics thermal drift, deadpath correction, cosine error; 2) The measurement uncertainty of this calibrator was computed according to GUM [2]. This uncertainty analysis was calculated when this calibrator was applied on a CNC lathe. The expanded uncertainty of this calibrator was ±2.96 μm for a measured distance of 1 m and nominal pitch of 10 mm with the machine at temperature of 20℃. This uncertainty is based on a combined standard uncertainty multiplied by a coverage factor k_(95) = 2, providing a level of confidence of approximately 95%.