Patent ID: 6705156
Filing Date: 2004-03-16
Classification: G01M

Abstract:
A method to identify and remove a machine contribution from tire uniformity measurements made on a tire uniformity machine (110) which subjects a tire (116, 116â€²) to normal conditions of mounting, inflation, load and rotational speed while measuring and collecting tire uniformity measurement data with respect to a rim reference mark (131), the method characterized by the steps of:step 1: mounting a tire on the tire uniformity machine at a random angular position with respect to the rim reference mark; step 2: collecting tire uniformity data to record a first measurement of uniformity data set; step 3: re-mounting the same tire on the tire uniformity machine at a random angular position with respect to the rim reference mark; step 4: collecting tire uniformity data to record a repeated measurement of uniformity data set; step 5: determining if additional measurements of uniformity are required for the tire, then looping back to repeat steps 3 through 5 if additional measurements of uniformity are determined to be required, but proceeding to step 6 when it is determined that additional measurements of uniformity are not required; step 6: calculating cross-correlation functions and using them to determine angular shifts between the first measurement data set and each of the repeated measurement data sets; step 7: using the angular shifts to synchronize each repeated measurement data set with the first measurement data set to yield synchronized measurement of uniformity data sets; and step 8: averaging together the first measurement of uniformity data and all of the synchronized measurement of uniformity data sets to yield an average tire uniformity data set that has minimized both random measurement noise and machine contribution errors in the measurement of uniformity data for the tire.