Allowable deviations from the normal shape of surfaces undergoing processing

摘要

This paper analyzes how the rms wavefront deviation from the nominal shape is interconnected with the character of the deformation of surfaces undergoing processing, modelled by means of a power series, Zernike polynomials, and Chebyshev polynomials for a constant value of the peak-to-valley wavefront deformation. The region of values of the rms wavefront deviation is determined within which these values can be legitimately used to estimate the achieved quality of the surface shape. A possible relationship of the rms deviation and the peak-to-valley wavefront deformation is established.