A new convex-hull based approach to evaluating flatness tolerance

In this paper, we consider a minimum-zone evaluation problem for flatness to determine the minimum tolerance zone enclosing all the measurement points obtained from a surface. For the problem, a new geometric approach called the 'convex-hull edge method' (CONHEM) is proposed. The method guarantees the minimum zone tolerance for a given set of measurement points. Several examples discussed by other researchers are illustrated to compare the method with some existing approaches. (C) 1997 Elsevier Science Ltd. All rights reserved.