TY - GEN
T1 - Reconciling the differences between tolerance specification and measurement methods
AU - Vemulapalli, Prabath
AU - Shah, Jami J.
AU - Davidson, Joseph K.
PY - 2013
Y1 - 2013
N2 - The ASME Y14.5M standard has defined different types of tolerances that can be applied to a feature to achieve the required functionality. Each tolerance defines a zone within which the feature under inspection must lie. The conformance of the parts to these tolerances is checked by manual measurements or a CMM. But it has been observed that the measurements between different CMMs do not match. There are two generally accepted reasons for this discrepancy. The first one is the measurement uncertainty in CMM software. This problem was addressed by NIST by developing reference softwares for feature fitting algorithms. And the second one is the distinct choice of algorithms for fitting substitute feature to the data points measured from CMM. Feature fitting algorithms used in CMMs are often based on their mathematical convenience rather than the interpretation of definitions in the GD&T standard. Our research is focused on identifying that normative algorithm that is best to be used for each type of tolerance. Each normative algorithm is identified as the one to best represent the interpretation of geometric control as defined by the Standard and on the manual methods used for the measurement of a specific tolerance type.
AB - The ASME Y14.5M standard has defined different types of tolerances that can be applied to a feature to achieve the required functionality. Each tolerance defines a zone within which the feature under inspection must lie. The conformance of the parts to these tolerances is checked by manual measurements or a CMM. But it has been observed that the measurements between different CMMs do not match. There are two generally accepted reasons for this discrepancy. The first one is the measurement uncertainty in CMM software. This problem was addressed by NIST by developing reference softwares for feature fitting algorithms. And the second one is the distinct choice of algorithms for fitting substitute feature to the data points measured from CMM. Feature fitting algorithms used in CMMs are often based on their mathematical convenience rather than the interpretation of definitions in the GD&T standard. Our research is focused on identifying that normative algorithm that is best to be used for each type of tolerance. Each normative algorithm is identified as the one to best represent the interpretation of geometric control as defined by the Standard and on the manual methods used for the measurement of a specific tolerance type.
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U2 - 10.1115/MSEC2013-1206
DO - 10.1115/MSEC2013-1206
M3 - Conference contribution
AN - SCOPUS:84890280211
SN - 9780791855461
T3 - ASME 2013 International Manufacturing Science and Engineering Conference Collocated with the 41st North American Manufacturing Research Conference, MSEC 2013
BT - ASME 2013 International Manufacturing Science and Engineering Conference Collocated with the 41st North American Manufacturing Research Conference, MSEC 2013
T2 - ASME 2013 International Manufacturing Science and Engineering Conference Collocated with the 41st North American Manufacturing Research Conference, MSEC 2013
Y2 - 10 June 2013 through 14 June 2013
ER -