Assessing circularity in three dimensions

Citation
Sy. Chou et al., Assessing circularity in three dimensions, J MANUF SCI, 123(1), 2001, pp. 128-134
Citations number
12
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Mechanical Engineering
Journal title
JOURNAL OF MANUFACTURING SCIENCE AND ENGINEERING-TRANSACTIONS OF THE ASME
ISSN journal
1087-1357 → ACNP
Volume
123
Issue
1
Year of publication
2001
Pages
128 - 134
Database
ISI
SICI code
1087-1357(200102)123:1<128:ACITD>2.0.ZU;2-2
Abstract
This research resolves an inconsistency problem that arises from assessing circularity of workpiece measured by coordinate measuring machines (CMMs). Although the notion of circularity is employed to constrain two-dimensional circular features, in practice the measured points are obtained in a three -dimensional spare and are in general nor in the same plane, let alone bein g in a "perpendicular" cross-section. All of the algorithms currently used for assessing circularity deal with data in a single plane that is perpendi cular to the axis of a cylindrical feature from which the circular feature is extracted. This discrepancy causes the assessed circularity significantl y departing from the actual circularity and resulting in rejection of in-to lerance parts. This research designs a compensation procedure for deriving two-dimensional data from three-dimensional biased measured points. The cir cularity is assessed based on the compensated two-dimensional data points. The assessment results with the compensation are compared with those withou t compensation. A program containing a variety of implementations of form f itting algorithms is developed and used to illustrate the improvement on th e accuracy of assessment.