Sampling strategies for verification of freeform profiles using coordinate measuring machines

Verification of engineering components having freeform profiles on a coordinate measuring machine (CMM) requires accurate measurement of sufficient number of sample points. While the measurement accuracy increases with increased sample size, it is often limited by cost and time considerations. Thus, for a given sample size, the locations of the measurement points are to be determined such that the actual shape may be effectively characterized. Several attempts are reported in the literature. A simple algorithm based on dominant points is proposed in this paper. Simulation studies have been carried out on a freeform profile. Comparison of the results with those obtained from uniform spacing and equi-parameter sampling methods reveals that the proposed method performs effectively.