In view of the inefficiency of inspecting aero-engine blades with coordinates measuring machine

unified mathematical descriptions of common sampling algorithms were proposed based on lever system

meanwhile

an optimal sampling algorithm for airfoil surfaces inspection with coordinate measuring machine was presented. By introducing torsion information

the curvature-arc sampling algorithm was appropriate to space curves

and based on this

the algorithm for sampling cross sections on the blade surface through the leading and the trailing edge curves was proposed. And the optimization method of weights in curvature-arc sampling was researched also. Finally

several experiments for different blades were implemented

and the comparisons of optimal sampling points reconstruction errors with those of equal-parameter sampling

equal-arc sampling

curvature-based sampling

equal-deviation sampling and weighted curvature-based sampling were made. The results indicate that the accuracy of optimal sampling is 11.2% higher at least. And the number of optimal sampling points is 92.3% less than equal-step sampling which is used widely in practice.