Abstract
Nowadays a geometrical surface structure is usually evaluated with the use
of Fourier transform. This type of transform allows for accurate analysis
of harmonic components of surface profiles. Due to its fundamentals,
Fourier transform is particularly efficient when evaluating periodic
signals. Wavelets are the small waves that are oscillatory and limited in
the range. Wavelets are special type of sets of basis functions that are
useful in the description of function spaces. They are particularly useful
for the description of non-continuous and irregular functions that appear
most often as responses of real physical systems. Bases of wavelet
functions are usually well located in the frequency and in the time
domain. In the case of periodic signals, the Fourier transform is still
extremely useful. It allows to obtain accurate information on the analyzed
surface. Wavelet analysis does not provide as accurate information about
the measured surface as the Fourier transform, but it is a useful tool for
detection of irregularities of the profile. Therefore, wavelet analysis is
the better way to detect scratches or cracks that sometimes occur on the
surface. The paper presents the fundamentals of both types of transform.
It presents also the comparison of an evaluation of the roundness profile
by Fourier and wavelet transforms.
Go to article